Monochrome vs Color LCDs | Cost-Effectiveness, Power & Clarity

If extreme cost-effectiveness and battery life are paramount, black and white LCD is the first choice.

Its cost is usually only about 30% of that of a color screen, power consumption is as low as the microampere (uA) level, and it features high contrast and sharp fonts under strong light, making it extremely suitable for industrial instruments or medical equipment.

Although color LCDs can provide a rich multimedia interaction experience, their power consumption is typically 5 to 10 times higher than that of black and white screens, and the price is higher.

Cost-Effectiveness

The hardware procurement cost of a monochrome LCD is about 20% to 30% of a color TFT screen of the same size.

Taking a 2.4-inch screen as an example, the bulk unit price of a monochrome graphic dot matrix screen (128x64) is about $1.50, while an ordinary resolution IPS color screen costs more than $6.00.

The difference lies not only in the screen itself; the impact on system-level costs is even more significant: driving a monochrome screen requires only a $0.50 8-bit MCU (such as STM8) combined with less than 1KB of on-chip SRAM;

In contrast, color screens usually require a high-performance 32-bit MCU (such as the STM32F4 series) and external DRAM to handle the Framebuffer, which increases the total bill of materials (BOM) cost of the PCBA (Printed Circuit Board Assembly) by more than $10.

Panel Procurement

On the price lists of electronic component distributors (such as Digi-Key or Mouser), the price difference between monochrome and color screens usually starts at 5 times.

Taking a standard 2.4-inch screen as an example, the bulk purchase price for a monochrome graphic dot matrix screen with a resolution of 128x64 is approximately $1.50.

However, for a TFT color screen of the same size with a resolution of 320x240, even for a low-end TN panel, the procurement cost is at least between $6.00 and $8.00.

This huge price difference does not come from brand premiums, but from the hard costs of the physical structure, primarily reflected in the "layers" of the glass panel.

The structure of a monochrome screen is as simple as a sandwich, with liquid crystal sandwiched between two layers of glass, plus two polarizers, resulting in extremely high production yields.

But to display color, color screens must create millions of tiny transistor switches (TFT arrays) on the glass through photolithography processes.

This is like carving on a grain of rice; color screens usually require 5 to 7 high-precision photolithography exposure processes, whereas monochrome screens only need 4 simple masking steps.

Every extra photolithography step involves more chemical reagent consumption and equipment depreciation, directly leading to a 150% increase in the processing cost of glass substrates of the same size.

Besides the glass itself, color screens have an expensive side effect: they are effectively "sunglasses" with extremely low light transmittance.

Color screens must have a color filter layer attached. This film blocks about 70% of the backlight brightness. To make the screen visible, the backlight intensity must be increased.

Surge in LED Quantity: Monochrome screens usually only need 1 to 2 edge-lit LEDs to illuminate, and can even turn off the backlight completely outdoors relying on reflected light.
Optical Film Stacking: To counteract the blocking of the filter, color screens must use 6 to 8 high-brightness LEDs and a complex backlight group composed of 3 layers of brightness enhancement films and diffusers.
Cost Proportion: For the backlight module alone, the material cost for a color screen is more than 10 times that of a monochrome screen.

The complexity of backlight components not only pushes up the unit price but also increases assembly difficulty and scrap rates.

On the production line, monochrome screens are almost "bulletproof" products, with a simple and durable structure, and the factory yield rate has long been stable at over 98%.

However, due to the high density of pixels in color screens, any tiny dust particle falling on a transistor will cause a permanent "dead pixel" on the screen.

To digest these rejects, panel factories divide screens into Grade A (perfect) and Grade B (with 1-3 dead pixels), and the purchase price difference between the two is usually between 20% and 30%.

This poses a difficult problem for purchasers: to ensure product reputation, they usually must pay a high price for Grade A screens, or spend extra labor costs to screen out Grade B screens.

If you think the price difference for standard products is acceptable, then once "resizing" or "reshaping" is involved, the cost difference becomes staggering.

Many medical instruments or industrial control equipment require screens with special aspect ratios, or need to permanently display specific icons (such as battery level bars) on the screen glass.

Monochrome Screen Customization: The cost of opening a set of molds (NRE) is usually only $800 to $1,500, which can be completely amortized in small batch production.
Color Screen Customization: To change the size of a TFT panel, the NRE fees for photomasks and backlight molds start at $50,000.
MOQ Threshold: Monochrome screen customization can be done with 1,000 units, while color screens usually require a commitment to purchase more than 50,000 units.

This high customization threshold forces the vast majority of non-consumer electronic products to compromise and use obsolete inventory screens designed for mobile phones available on the market.

Using inventory phone screens is cheap, but it faces huge supply chain risks: the lifecycle of these screens is very short.

The consumer electronics market changes extremely fast. A TFT screen may be discontinued (EOL) after 18 months of production, and manufacturers will force you to revise your design.

Once the screen is discontinued, you must look for alternatives, which involves not only repurchasing but also engineers redesigning the circuit board and rewriting driver code.

The validation fees, prototype testing fees, and potential production line stoppage risks during this process are all invisible "hidden procurement costs."

In contrast, monochrome screen technology has hardly changed in the past 20 years. For many industrial controllers designed in 2005, completely compatible screens can still be bought today.

This supply stability lasting over 15 years gives monochrome screens an unbeatable advantage in Total Cost of Ownership (TCO).

Finally, the flexible printed circuit (FPC) connecting the screen to the motherboard is also an easily overlooked cost trap.

Color screens need to transmit huge amounts of image data, typically using connectors with 40 to 50 pins, or expensive Board-to-Board connectors.

The cost of a single one of these high-density connectors can be as high as $0.50, and they have higher requirements for the gold plating process of the circuit board.

Monochrome screens usually only need 10 to 14 pins, and can even use the cheapest zebra strips (conductive rubber) to press directly onto the circuit board, with connection costs being almost zero.

Supporting Hardware

In the 2024 component market, a basic 8-bit microcontroller priced at only $0.40 can perfectly drive a 128x64 monochrome screen.

This cheap chip usually has only 2KB of memory (RAM), but this is enough to hold all the display data required for a monochrome screen.

Once switched to a color TFT screen, it is like forcing a Ferrari engine into a tractor; the entire hardware system must be rebuilt.

Every pixel of a color screen needs red, green, and blue data to describe it. The data volume grows explosively, forcing you to buy expensive high-performance chips.

To prevent color images from stuttering, it is usually necessary to choose a 32-bit high-speed processor, with a purchase unit price generally between $2.50 and $4.00.

This directly causes the cost of the processor alone to skyrocket by over 500%, but this is just the beginning; the bigger pitfall lies in memory.

Monochrome screens only need to remember two states: "on" or "off." The data volume for a full screen is very small and can fit completely into the processor's built-in cache.

However, the data for a single frame of a color screen is huge. If the processor's built-in memory is not large enough, the screen will tear or fail to display.

The table below intuitively shows the hard demand for processor memory (RAM) by different screens to "remember" a static image:

Screen Type	Resolution	Pixel Depth	Single Frame Memory Usage	Estimated Processor Cost
Monochrome Dot Matrix	128 x 64	1-bit	1 KB	$0.50 (Entry Level)
Color QCIF	176 x 144	16-bit	50 KB	$1.50 (Mid-range)
Color QVGA	320 x 240	16-bit	153 KB	$3.00 (High-end)
Color HVGA	480 x 320	24-bit	460 KB	$5.00+ (Requires External Memory)

From the table, it can be seen that a common 3.5-inch color screen needs at least 153KB of memory to store a single image.

Cheap processors on the market usually only have 20KB to 64KB of memory, which cannot drive a color screen at all, forcing engineers to attach independent memory chips.

This external SDRAM chip not only occupies circuit board space but also adds about $1.20 in material costs and extra soldering fees.

In addition to RAM, the hard disk space (Flash) used to store icons and background images is also a big money burner for color screens.

Fonts and icons for monochrome screens are very small; a few KB can store the interface of the entire system without spending extra money on storage chips.

But a set of UI for a modern color interface contains a large number of high-definition images, with capacity easily exceeding 8MB, requiring the additional purchase of a SPI Flash chip.

This adds another $0.80 expense to the bill, and also makes the wiring on the circuit board unusually complex.

Monochrome screens usually only need 2 wires (I2C interface) to communicate with the processor, just like a rural dirt road—simple and not prone to accidents.

To transmit massive amounts of data, color screens usually need 16 or even 24 parallel data lines, which is like building a 24-lane highway on a circuit board.

Such dense wiring cannot be laid out on single-layer or double-layer circuit boards. Forced wiring will cause severe signal interference, causing "snow" on the screen.

To solve this problem, engineers are usually forced to upgrade the circuit board from a cheap 2-layer board to an expensive 4-layer or 6-layer board.

According to the average quotes in the PCB manufacturing industry in 2023, the processing cost per square inch for a 4-layer board is about 60% higher than that for a 2-layer board.

Besides the board becoming more expensive, the cost of the physical interface (connector) connecting the screen and motherboard also rises linearly with the number of lines.

Monochrome screens have few pins and can even use conductive rubber strips costing a few cents to press directly onto the board, making the cost almost negligible.

Those dozens of wires for color screens must use precise FPC connectors. The cost of a single such socket is about $0.30, and the requirements for the soldering process are extremely high.

Finally, to make the color screen light up, the power system must also undergo a thorough "overhaul."

Monochrome screens are very power-efficient and usually work stably directly with two dry batteries or the system's own 3.3V power supply.

The flipping of liquid crystal molecules inside a color screen requires special positive and negative high voltages (+15V and -10V), and the backlight requires extremely high driving voltage.

A dedicated power management chip (PMIC) and a backlight driver chip must be added to the circuit board.

This set of power conversion circuits not only increases design difficulty but also introduces additional chip and inductor costs of about $0.60.

So, when you decide to upgrade from a monochrome screen to a color screen, it is not just that the screen is more expensive; the cost of peripheral supporting hardware will increase by at least $10.

Customization Fees

In the design world of electronic products, off-the-shelf standard screens are often like "one-size-fits-all" clothes, making it difficult to perfectly fit the unique curves or dimensions of the product casing.

If you want to make a well-fitting "bespoke suit" for your product, the threshold for monochrome screens (like the kind on calculators) is surprisingly low, making them very suitable for startups.

According to average quotes from the global supply chain in 2024, the cost for a full set of custom molds for a monochrome LCD screen is typically only between $800 and $1,500.

This money buys more than just dimensions; it allows you to "carve" the company logo, special battery icons, or specific text directly onto the glass, just like drawing.

This practice is extremely smart because these fixed patterns do not need the processor to draw them, greatly reducing the pressure on software engineers to write code and allowing the system to run faster.

Besides patterns, you can even have the factory cut the glass into shapes like circles or octagons, or drill a hole in the middle for a knob to pass through; this type of irregular cutting is very mature for monochrome screens.

The production process for monochrome screens is very "robust," and the yield rate for irregular cutting can usually be maintained at over 95%, so factories often only require a Minimum Order Quantity (MOQ) of 1,000 units.

But if you want to do the same customization for a color TFT screen, it is like asking a car manufacturer to redesign the chassis for you alone; the cost will explode instantly.

Manufacturing color screens requires micron-level photolithography on glass, which necessitates the creation of 5 to 7 layers of extremely expensive photomasks, each as precise as a film negative.

Just to change the aspect ratio or resolution of a TFT panel requires remaking the entire set of photomasks. This "entry fee" is usually between $150,000 and $250,000.

Besides this huge sum, you also have to redesign complex driver circuits, which is something usually only giants like Apple or Samsung, with sales of over 100 million units a year, can afford to play with.

For most small and medium-sized enterprises, if the standard screen size is not suitable, they usually have to settle for the next best thing: don't change the glass, only modify the ribbon cable (FPC) connecting to the motherboard.

Although this "semi-customization" is cheap, with mold modification fees for the ribbon cable around $1,000 to $3,000, it does not solve the fundamental problem of the screen size not matching the casing.

Even more troublesome is that the backlight module of a color screen is also a money burner. If brightness or viewing angles need adjustment, molds for the metal frame and light guide plate must be reopened.

The cost for this set of backlight molds is usually between $5,000 and $10,000. Although cheaper than modifying the glass, it is still a heavy burden for small-batch products.

More discouraging than the mold fees is the "Minimum Order Quantity (MOQ)." Once a TFT panel factory's production line starts, the daily operating cost is extremely high, and it must run continuously.

Even if you are willing to pay the $200,000 mold fee, most TFT panel factories will still force you to sign a contract to purchase 50,000 to 100,000 units.

This creates a deadlock: many high-end medical devices or industrial instruments might only sell 20,000 units in their entire lifecycle, making it impossible to consume so many screens.

Therefore, engineers are forced to abandon customization and turn to buying "excess capacity" screens produced for smartphones available on the market, also known as "standard products."

Although using these standard products avoids high customization fees, it introduces a huge hidden danger: these screens are designed for fast-moving consumer goods and have extremely short lifespans.

The market life of consumer TFT screens averages only 18 to 24 months. Once the phone manufacturer stops production, this screen will immediately disappear from the market.

When a screen reaches End-of-Life (EOL), equipment manufacturers are forced to modify casing molds, redraw circuit boards, and have the software team re-adapt drivers for a new screen.

This "passive upgrade" caused by screen discontinuation may happen repeatedly, 3 to 4 times during a product's 5 to 10-year lifecycle, costing money every time.

Power

Color TFT screens have low optical efficiency; their internal color filters block approximately 65% to 75% of light, so they must rely on high-brightness LED backlights to make content visible. The backlight typically consumes 80% to 90% of the module's total power.

Lighting up a standard 3.5-inch TFT screen usually consumes a current between 120mA and 180mA. In contrast, monochrome LCDs directly utilize ambient light for display without needing the backlight to be constantly on.

Their current for maintaining a static image is extremely low, typically requiring only 5uA to 20uA. For devices using a 225mAh CR2032 coin cell battery, a monochrome screen can work continuously for months or even years, whereas a color screen can usually only last 1 to 2 hours.

Backlight Reliance

The first obstacle light encounters is the polarizer, which acts like blinds, only allowing light from specific angles to pass. Just this one physical layer directly blocks about 50% of the initial light, instantly dimming the originally bright backlight by half.

Immediately after, the light has to pass through densely packed transistor circuit layers. On high-definition screens, these tiny circuits block the light path like the mesh of a screen window. typically, only 55% to 65% of the area is light-transmissive, with the rest blocked by metal wiring.

The most fatal checkpoint is the color filter, which determines why the screen is so power-hungry. To display red, the filter must absorb all green and blue light. This is like looking at the world through sunglasses; the filter forcibly intercepts about 66% of the light.

After this layer-by-layer exploitation, typically less than 8% of the strong light originally emitted by the LED remains to penetrate the screen surface and enter your eyes. To make you feel the screen is "bright enough," the backlight must work desperately, emitting more than 12 times the required light.

This explains why the back of a color screen is always warm. To maintain a reading brightness of 300 nits, the LEDs in the backlight module must run at full power like miniature searchlights, wasting the vast majority of electricity.

Energy Loss: More than 90% of battery energy does not turn into light but is absorbed by filters and converted into waste heat.
Current Demand: Lighting up a 4.3-inch screen typically requires current as high as 150mA, which is equivalent to lighting up 3 flashlights simultaneously.
Voltage Burden: To drive these LEDs, battery voltage must be forcibly boosted to over 18V, wasting another 15% of power during conversion.

Outdoors in sunlight, this "confrontational" lighting principle collapses completely. Sunlight intensity is as high as 100,000 lux. For a color screen to be visible, it must "fight against" the sun, cranking brightness up to 1,000 nits.

At this time, the mobile phone or dashboard will enter "high energy consumption mode," with power consumption instantly soaring to over 600mA. This not only drains the battery within 2 hours but the intense heat also accelerates battery aging, causing health to drop by 10% within a year.

In contrast, the monochrome LCD's working logic is completely different. It is not a transporter of light, but a "borrower" of light. Because it lacks that sunglasses-like color filter, the passage for light entry and exit is very clear, and light transmission efficiency is 3 times that of a color screen.

Most monochrome screens (like those on calculators or digital watches) are reflective. They have a mirror-like layer at the bottom of the screen that uses ambient light to illuminate itself. The brighter the surrounding environment, the stronger the light reflected back, and the clearer the screen looks.

Under ordinary indoor lighting of 500 lux, the monochrome screen's backlight can be turned off completely, dropping power consumption directly to 0 mW. At this time, it consumes extremely low power, merely to keep the image from disappearing, with a current of only 15uA.

Working Principle: Uses ambient light for reading, no need to consume battery energy to create light.
Contrast: Light passes through the liquid crystal layer twice (entry and reflection), making black and white contrast even sharper under strong light.
Night Mode: Even in a pitch-black environment, turning on just one weak side LED (about 5mA) makes it clearly visible.

This difference is vividly demonstrated in battery durability. In an outdoor equipment test in 2022, engineers compared two prototypes using the same 2000mAh lithium battery.

The device equipped with a reflective monochrome screen worked continuously for 45 days before running out of power, assuming 10 hours of use per day. Because it didn't need to turn on the backlight for the vast majority of the time, it was just "hitching a ride" on sunlight.

However, the device that switched to a color screen of the same size, even with auto-brightness enabled, shut down after only 14 hours under the same daylight conditions. To resist the sunlight, it had to drain all its power to keep the backlight bright.

Pixel Density

Put two types of screens under a microscope, and you will find that every pixel of a color screen is actually cut into three tinier fragments of red, green, and blue.

To prevent these three colors from mixing, "black walls" must be built between them during manufacturing. These black walls occupy precious space that could have allowed light to pass.

It's like installing very thick security bars on a window; the originally spacious glass is fragmented. In standard color panels, this physical structure results in an effective area for light passage of usually only about 55%.

The remaining light is all blocked by these security-bar-like circuits and isolation layers. To make up for the blocked light, the color screen must significantly increase the brightness of the backlight, just like turning on a brighter light inside a room to illuminate the outside.

According to an optical efficiency test in 2021, to make a color screen with 300 PPI density achieve the same brightness as a monochrome screen, the current output of the backlight LED was forced to increase by 3.5 times.

Monochrome screens don't have this trouble; one pixel is a complete large window without any traces of being chopped up. Light passes through it almost unimpeded, with an aperture ratio easily reaching over 85%.

Besides the physical structure blocking light, processing these densely packed pixel data is a major power drain. We can view the screen as a giant spreadsheet that needs filling.

Monochrome screens are very simple; each box is filled with either 1 (black) or 0 (white), and the data volume is extremely small. The processor handles it effortlessly, like just ticking boxes.

A color screen is a gluttonous data monster; each sub-pixel needs 8 to 16 bits of depth information to describe the shade of color. At the same 320 x 240 resolution, refreshing a frame of a monochrome image only requires transmitting 9.6 KB of data.

Once switched to 16-bit color mode, for the same frame, the data volume instantly swells to 153.6 KB. The main control chip (MCU) must move 16 times the amount of data, forcing it to run at full speed.

This difference in data throughput directly determines how busy the processor is. Color screens usually need to refresh constantly at a frequency of 60Hz, even if the image is static.

The processor has to send the same data to the screen 60 times per second, like on a non-stop treadmill, never able to stop.

Monochrome LCDs, especially models with integrated video memory, have a "display and hold" characteristic. Once data is sent, the processor can stop working completely and enter deep sleep.

This difference causes system standby current to drop precipitously from 25mA to below 10uA. The table below illustrates the huge chasm between the two technologies in data processing and power consumption at the same resolution:

Comparison Dimension	Monochrome LCD (1-bit)	Color TFT (16-bit RGB)	Power Consumption Impact
Single Frame Data Packet	9.6 KB	153.6 KB	Huge data volume forces the CPU to work non-stop like a mover.
Refresh Mechanism	Refresh on Demand (0Hz)	Continuous Refresh (60Hz)	Screen doesn't rest, causing circuits to be always busy and powered.
SRAM Cache	< 10 KB	> 150 KB	Large capacity cache needs continuous power, increasing extra leakage current.
Interface Speed	Low Speed SPI (1-5 MHz)	High Speed RGB (20+ MHz)	High-frequency signal toggling generates extra heat on line impedance.

This pixel-level data pressure is particularly evident in wearable devices like smartwatches. The battery space in a watch is very limited, with capacity usually only around 300mAh.

If a high-pixel-density color screen is used, to maintain fine images, the graphics processor (GPU) must be on standby at all times. Yet when displaying simple step counts or time, this high computing power is actually a huge waste of resources.

In contrast, low-pixel-density monochrome screens allow the system to "slack off" most of the time. In an endurance test in 2023, a sports watch using a memory LCD performed amazingly.

The sleep time ratio of the main control chip reached 99.2%; the chip only worked at full speed during the few milliseconds when the user pressed a button.

Battery Selection

To drive backlight LEDs and refresh tens of thousands of color pixels, TFT modules typically need to draw a pulse current exceeding 120mA from the battery at the moment of startup.

This instantaneous high current demand directly sentences those lightweight, cheap coin cell batteries to "death," because the chemical structure of coin cells simply cannot withstand this kind of critical hit.

The most common CR2032 coin cell battery has a designed continuous discharge current of only 3mA, and its limit pulse can only barely maintain around 15mA.

If you forcibly use a coin cell battery to drive a color screen, the chemical reaction speed inside the battery cannot keep up with the speed of current extraction.

This causes the battery voltage to dive instantly, falling directly from 3.0V to below 2.0V. For electronic devices, this voltage drop is equivalent to cutting off the power directly, and the system will reset or shut down immediately.

So as long as a color screen is chosen, engineers have no choice but to use Lithium-Ion (Li-Ion) or Lithium-Polymer (Li-Po) batteries which are bulkier and more costly.

Although these batteries can easily output large currents of over 500mA, they bring heavy "baggage"; lithium batteries are extremely delicate and must be equipped with a specialized protection circuit board (BMS).

This extra circuit board is responsible for monitoring voltage to prevent the battery from becoming a "small bomb" due to overcharging or becoming scrap due to over-discharging, which undoubtedly increases the physical volume of the device and about 15% in hardware costs.

In 2022 supply chain data, the cost of a complete lithium battery power management solution is more than 8 times the cost of a coin cell holder.

Besides the battery itself, color screens also require complex voltage converters. Monochrome screens usually only need 3.0V to work directly, matching perfectly with two dry batteries.

Color screen backlight strings typically need 18V or even higher voltage to light up, which requires installing a Boost Converter on the circuit board.

During the process of moving the 3.7V lithium battery voltage to 18V, this converter wastes about 15% of energy in vain due to heat loss.

In contrast, the monochrome LCD's demand for power is "slow and steady," especially reflective screens, whose demand for current is extremely smooth with almost no peaks.

When displaying static images, its current consumption can be as low as 5uA. This value is smaller than the "self-discharge" current of many batteries when stored naturally.

Battery life no longer depends on how much electricity the screen uses, but on how long the battery can store itself.

Industrial-grade Lithium-Thionyl Chloride (Li-SOCl2) batteries, combined with monochrome screens, can achieve a theoretical standby life of up to 10 years.

This characteristic allows monochrome screens to dominate in fields like medical patches or smart water meters. Users don't need to remember to charge them, or even know there is a battery inside.

In an insulin pen logger released in 2023, engineers used only a single 225mAh coin cell battery to maintain the device's normal display for 3 years.

If switched to a color OLED screen of the same size, with the same battery capacity, calculated at 20 views per day, the device would be completely dead within 4 days.

Color screens force products to become "charging slaves," where users must constantly monitor remaining power and carry charging cables.

Monochrome screens, however, make the power source a "forgotten" component. For those devices that need to run stably for a long time and do not want to be disturbed by maintenance, this is the ideal state.

Clarity

Clarity is determined by pixel integrity and optical contrast. Monochrome screens have no sub-pixel division, providing 100% effective resolution at the same size, with text edge sharpness 3 times higher than that of color screens.

FSTN technology can achieve a contrast ratio of 20:1 at 25 degrees Celsius, while although color TFTs have a nominal value of 500:1, under 100,000 lux of direct sunlight, the reflectivity of transflective monochrome screens maintains above 10%, far exceeding the 4% light penetration efficiency of color screens.

Pixel Arrangement

Every pixel is a complete square "window" where liquid crystal molecules can open or close 100%. Light passes through with almost no physical obstruction, making the edges of the displayed image as sharp and solid as printed matter.

Color screens are completely different. To display color, they must forcibly cut that complete square window into three narrow vertical strips of red, green, and blue. This is like installing a layer of fine metal mesh on a window; these isolation bars known as the "Black Matrix" not only fragment the image but also occupy extremely valuable physical space on the screen.

Light Path Comparison: The "window" aperture ratio of monochrome FSTN panels is as high as 85% to 92%, making the light path extremely clear.
Physical Obstruction Rate: Due to complex transistor circuits and isolation bars, only 45% to 55% of the area of color TFT panels can transmit light.
Energy Waste: More than half of the light emitted by the bulb behind the color screen directly hits these physical structures and is wasted.

This structural "fragmentation" reveals obvious defects when displaying fine lines. When you try to draw a 1-pixel wide black line on a color screen, the screen actually turns off three unconnected sub-pixel strips, interspersed with physical gaps that cannot display content, causing the lines seen by the naked eye to be discontinuous and full of microscopic jaggedness.

To cover up this physical discontinuity, color screen software must use "anti-aliasing" technology, which is to intentionally fill some gray pixels at the edges to blur the jaggedness. This is like smudging pen writing a little with a finger; although it looks smooth, it actually loses its original sharpness, causing small fonts to always look hazy like frosted glass.

Edge Precision: The internal fill rate of monochrome screen lines is 100%, without any physical break points, requiring no software blurring processing.
Gap Width: There is a physical dead zone of 10 to 18 microns between sub-pixels of color screens, which is the root cause of visual blur.
Reading Test: In the ISO 9241-303 standard test, the recognition accuracy of monochrome screens for small characters below 8pt is 18% higher than that of color screens.

In addition to the physical structure blocking light, color screens must also wear a pair of "sunglasses." This color filter layer attached inside absorbs 2/3 of the energy in the spectrum, allowing only specific colors to pass, which further kills light penetration, causing color screens to always look gray when not powered or when the backlight is dim.

In contrast, monochrome screens remove these "sunglasses," allowing light to directly penetrate the liquid crystal layer and reflect back. Under the same ambient light, the brightness utilization of monochrome screens is more than 5 times that of color screens, explaining why digital watch screens are extremely clear in the sun, while phone screens need brightness cranked to max to be barely visible.

Light Transmission Efficiency: The total light transmittance of standard color panels is only 4% to 7%, with huge light energy loss.
Monochrome Advantage: After removing the filter, monochrome panel transmittance soars to 30% to 35%, with naturally higher contrast.
Aging Performance: Non-organic filter monochrome screens show no yellowing or discoloration after working continuously for 1000 hours at 85°C high temperature.

Human eye physiology also prefers simple monochrome light. Because light of different colors has different wavelengths, the focal point of the eyeball actually deviates slightly when focusing on red light and blue light. Staring at white text composed of color pixels for a long time requires the brain to constantly fine-tune focus to synthesize the image, which is an unconscious visual burden.

Outdoor Vision

Sunlight pours down like a flood, with intensity typically between 30,000 and 100,000 lux. Under this violent light, your color screen that is bright and beautiful indoors will instantly become a dark mirror, showing nothing.

This is because standard color screens rely on LED lights behind them to emit light, with brightness typically only 300 to 500 nits. This is like trying to see a faint candle flame clearly while car high beams shine directly into your eyes; the backlight is completely drowned out by sunlight.

The monochrome screen's strategy for dealing with sunlight is completely different; it does not confront it but uses its power. Most outdoor monochrome screens use "transflective" technology, with a special reflective film sandwiched on the back of the screen, which reflects incoming sunlight back like a mirror to illuminate the black writing on the liquid crystal layer.

With this design, the stronger the environmental light, the brighter the screen background, and the clearer the text becomes. Under 80,000 lux of strong light, the contrast of a fully reflective monochrome screen can easily soar to 15:1, while the contrast of an ordinary color screen at this time is not even 2:1.

If you insist on making a color screen visible outdoors, you must violently increase backlight brightness. This requires cranking brightness up to over 1000 nits, resulting in battery power draining like leaking water, and device heat generation increasing sharply, turning it into a hot brick.

A 3.5-inch high-brightness outdoor color screen may consume as much as 1.5 Watts of power. In contrast, a monochrome screen of the same size uses reflected light to work, consuming only 50 to 100 milliwatts of electricity, like the endurance gap between a marathon runner and a sprinter.

Besides brightness issues, the screen's construction itself is key. A color screen is like a sandwich with too many layers, containing a touch layer, color filter, and polarizer. The refractive index of each material layer is different, causing multiple reflections when light passes through, leading to severe glare on the screen surface even with a film applied.

Industrial tests show that the surface reflectivity of this multi-layer stacked structure is as high as 8% to 12%. This reflected light shrouds the image like fog, while a simple structured monochrome screen combined with anti-glare treatment can suppress reflectivity to below 2%.

Sunlight brings not only light but also deadly high temperatures. When a black screen is exposed to the scorching sun, the surface temperature climbs rapidly. The complex organic filter materials and liquid crystal mixtures inside color screens are very delicate; once overheated, liquid crystal molecules go into chaos, and the screen either turns black or develops permanent yellow spots.

The temperature tolerance limit of ordinary color panels is usually around 60°C, known as the "clearing point." Wide-temperature monochrome screens designed for outdoors use special chemical formulas and can display normally under extreme temperature differences from -30°C to +85°C, completely unafraid of sun exposure.

Invisible ultraviolet (UV) rays are also invisible killers of screens. The red, green, and blue dyes in color pixels are chemically similar to dyes on clothes and will decompose and fade under strong ultraviolet radiation. Over time, the image on a color screen will turn yellow overall, look old, and colors will become inaccurate.

Accelerated aging tests conducted according to ASTM G154 standards show that color filters develop obvious cracks and discoloration after 500 hours of UV irradiation. Monochrome screens, composed mainly of glass and metal, remain as clear as new after withstanding 1000 hours.

This durability is directly related to your wallet and maintenance frequency. If you are maintaining an outdoor parking meter or a dashboard on a boat, the last thing you want to see is the screen breaking after just one summer. The simple construction of monochrome screens gives them an extremely high survival rate in harsh environments.

Contrast

When you look at your phone in a dark bedroom, even if the screen displays a pure black image, do you always feel the screen emitting a faint gray glow? This is the "light leakage" phenomenon that color screens cannot avoid. Because the light (backlight) behind the color screen is always on, even if the liquid crystal layer tries desperately to block the light, there will always be some that slips through the complex filters.

Screen Type	How Black is Black (cd/m²)	Contrast (Typical)	Visual Feel
Ordinary Color Screen (TN)	1.0 - 1.6 (Obviously gray)	500:1	Like covered with a gray veil
High-end Color Screen (IPS)	0.5 - 0.6 (Dark gray)	1000:1	Can still see the screen is on
Monochrome Screen (VA Negative)	< 0.05 (Almost pure black)	3000:1	Like words floating on a black hole

This light leakage is called high "Black Level" in the professional field. Monochrome screens using Vertical Alignment (VA) technology allow liquid crystal molecules to stand completely vertically like blinds, blocking the light from behind tightly, with a light leakage rate of less than 5% of color screens.

Monochrome VA screens can create a background that is deep black. Against this pure black background, white characters are as sharp and bright as stars in the night sky, with contrast easily soaring to over 3000:1, which is 6 times that of ordinary color screens.

This extreme contrast is crucial for scanning dashboards. The human eye's sensitivity to this high-contrast edge far exceeds that of color. According to the ISO 9241-303 standard, when screen contrast increases from 10:1 to 100:1, your speed of reading data can increase by 15%, which may be the guarantee of safety when driving or operating machines.

Ordinary color screens often "die in the light" under sunlight; surface reflections and backlight leaking from inside mix together, turning the image white and washing it out, causing contrast to drop instantly below 2:1, making it basically impossible to see anything clear.

Ambient Light (Lux)	Color Screen Performance	Monochrome FSTN Screen Performance	Remarks
50 (Dim)	Background gray, glaring	Background pure black, comfortable	Monochrome wins night mode
500 (Office)	Fair, requires high brightness	Clear, no backlight needed	Monochrome saves more power
100,000 (Direct Sun)	Completely washed out, unreadable	Extremely sharp, strong reflection	Monochrome uses sunlight to enhance contrast

Monochrome FSTN screens, however, can stage a comeback against the wind. It uses a special transflective technology to reflect incoming sunlight back to use as backlight. The stronger the sunlight, the brighter the screen background, while the black text remains black, resulting in even higher contrast.

This is like reading a newspaper under the sun; the more light, the clearer the words. Under 100,000 lux of direct strong light, the contrast of a monochrome screen can still be maintained at around 15:1, without needing to frantically consume power to fight the sun like a color phone.

Besides being purely black, monochrome screens are also clearer when viewed from the side. If you look at an ordinary color screen (TN panel) from the side at more than 30 degrees, the colors will look weird, or even invert black and white. VA monochrome screens maintain a contrast as high as 1000:1 even at a large angle of 70 degrees.

Whether it's a thermostat on the wall or a coffee machine screen, whether you look at it standing, sitting, or sideways, the image is equally sharp and clear without dead angles. For those fixed-position devices where the angle cannot be adjusted, this is simply a lifesaver.

There are even more advanced monochrome OLED (PMOLED) screens where each pixel emits its own light, and black areas are completely unpowered, truly pure black. In tests in 2023, the clarity score of this screen when displaying pure text was 40% higher than that of color screens.