Greyscale Test
Display 256-level greyscale ramps to detect color tint, shadow crushing, and highlight clipping. A neutral grey ramp is the most sensitive test of color balance.
Crushed blacks hide detail. Tint = poor gamma.
Should appear neutral grey — no color cast.
Blown whites lose detail. Pink/blue tint = defect.
Why use this color tool
256-step greyscale ramp
Full 8-bit ramp from black (0) to white (255) with each step labeled. Spot crushed shadows and blown highlights instantly.
10-bit ramp option
1024-step ramp for 10-bit panels. Banding here means your display or GPU pipeline is limited to 8-bit.
Per-channel grey balance
Pure grey versus tinted grey patches reveal if your white point is shifted toward red, green, or blue.
Calibration reference marks
Steps 16, 64, 128, 192, and 240 marked as reference levels for gamma calibration.
What is color
Greyscale is the range of neutral tones between black and white. A perfectly calibrated display renders every grey level as truly neutral — equal parts red, green, and blue. Real displays almost always show some color tint in greyscale, especially in shadows (which tend toward blue) and highlights (which tend toward yellow).
Greyscale testing reveals three things: color balance (is grey actually grey?), shadow detail (can you distinguish steps 1-16 from pure black?), and bit depth (does the ramp show smooth gradients or visible bands?). A 256-step ramp tests all three at once.
Most monitor issues show up in greyscale before they show up in color photos. A slight blue tint in shadows that you'd never notice in a photo becomes obvious when the screen displays a grey ramp. That's why professional calibrators always start with greyscale before touching color.
How to test
Step 1: Display the 256-step ramp
Open the test and select 256 levels. The ramp fills the screen from black on the left to white on the right.
Step 2: Check shadow detail
Can you distinguish steps 1-10 from pure black? If they all blend into black, your brightness is too low or the panel crushes shadows.
Step 3: Check highlight detail
Can you distinguish steps 246-255 from pure white? If they all blend into white, your contrast is too high or the panel clips highlights.
Step 4: Check for tint
Stare at each grey step. Does any step look slightly pink, green, blue, or yellow? Note the level where tint is most visible.
Step 5: Test 10-bit if supported
Switch to the 1024-step ramp. If it looks smoother, your display is 10-bit. If it bands identically, you're limited to 8-bit.
Common causes of color issues
White point drift
Backlight spectrum shifts as LEDs age, pushing grey toward warm (yellow/red) or cool (blue) over time.
Gamma misalignment
Wrong gamma crushes shadows (gamma too high) or washes them out (gamma too low). Aim for 2.2.
Panel bit depth limits
6-bit + FRC panels show banding in fine ramps. True 8-bit and 10-bit panels render smooth gradients.
GPU output range
Wrong GPU output range (Limited 16-235 vs Full 0-255) crushes shadows and clips highlights. Always use Full for PC monitors.
Frequently asked questions
Testing tips
- Test in a dim room — ambient light masks subtle tint differences in shadows.
- Stare at each grey step for 3-5 seconds; tint perception takes time to register.
- If shadows crush, raise brightness slightly; if highlights clip, lower contrast.
- Always set GPU output to Full RGB (0-255), not Limited (16-235), for PC monitors.
Related tools
Understanding Greyscale Banding: 6-bit vs 8-bit vs 10-bit
You display a smooth grey ramp on your monitor and notice visible steps — distinct bands of grey instead of a continuous gradient. Is your monitor broken? Probably not. It's just showing the limits of its bit depth, and understanding that limit is key to choosing the right panel for your work.
Bit depth is the number of distinct brightness levels a display can render per channel. A 6-bit panel can show 64 levels per channel (2^6), an 8-bit panel 256 levels (2^8), and a 10-bit panel 1,024 levels (2^10). With three channels (RGB), 8-bit yields 16.7 million colors and 10-bit yields 1.07 billion. More levels means smoother gradients and fewer visible bands.
Run the greyscale test with the 1024-step (10-bit) ramp. If the ramp looks smooth, your display is 10-bit. If it shows clear bands matching the 256-step ramp, you're limited to 8-bit. If even the 256-step ramp bands badly, you have a 6-bit panel — possibly with FRC dithering trying to fake 8-bit. Each result tells you what your panel can actually deliver.
6-bit + FRC panels use temporal dithering — rapidly flickering pixels between adjacent levels — to simulate intermediate shades. From normal viewing distance, the dithering is invisible and the gradient looks smooth. But the 1024-step test exposes the truth: a 6-bit+FRC panel cannot render the 768 intermediate levels between 8-bit and 10-bit. The bands are still there; you just can't see them at 256 steps.
Does bit depth matter for your use case? For gaming and general use, 8-bit is plenty — most games target 8-bit color, and the difference is invisible in motion. For photo and video editing, especially HDR work, 10-bit is essential — gradients in skies, sunsets, and shadows show clear banding at 8-bit. Professional monitors are 10-bit; budget monitors are 8-bit; the cheapest are 6-bit+FRC.
Verify your full pipeline supports 10-bit. A 10-bit monitor with an 8-bit GPU output still produces 8-bit color. Use DisplayPort (not HDMI 1.4), enable 10-bit output in your GPU control panel, and use a color-managed application like Photoshop or DaVinci Resolve. Pair the greyscale test with our gradient test and color depth test for a complete bit-depth audit.
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