Monitor Color Test

Press Go full screen and step through the color ladders: every step should look different from the next.

Pattern Pick one, then go full screen.

What to look for

F goes full screen. Escape leaves.

Red ladder, 16 steps to full red

Red ladder, 16 steps to full red

Preview · scaled to fit

Sixteen flat bars of red alone, from level 15 to level 255, each 16 levels above the last. Every bar should look brighter than the one on its left, and the first should stand clear of a black bezel in a dim room.

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1 of 10

Click, tap or press the right arrow for the next one. The left arrow goes back.

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What to look for

What you see and what it means

What to change on a computer

Next step Next: pixel grids for sharpness and scaling

All 24 patterns and checks

Patterns the page draws 10

  • Red ladder, 16 steps to full red Sixteen flat bars of red alone, from level 15 to level 255, each 16 levels above the last. Every bar should look brighter than the one on its left, and the first should stand clear of a black bezel in a dim room.
  • Green ladder, 16 steps to full green The same sixteen levels in green alone. Green carries most of a screen's brightness, so its dark steps are the easiest to see. A ladder that climbs evenly here and unevenly in red or blue points at one channel, not the whole screen.
  • Blue ladder, 16 steps to full blue Sixteen levels of blue alone. Blue is the dimmest channel, so its lowest bars sink into black first. A night mode shows here at once: the whole ladder gets darker.
  • Color pairs, six colors beside their half-strength twins Twelve bars: red, yellow, green, cyan, blue and magenta at full strength, each followed by the same color at level 128. Half the signal gives about 22 percent of the light, so every twin should look much darker than its partner.
Show all 24 patterns and checks (20 more)

Patterns the page draws, continued

  • Hue row, twelve hues round the color wheel Twelve hues 30 degrees apart at full strength: red, orange, yellow, chartreuse, green, spring green, cyan, azure, blue, violet, magenta and rose. Each should differ plainly from both its neighbors.
  • Top of red, levels 240 to 255 Sixteen bars of red one level apart, the last sixteen of the 256. The differences are small by design. Step back: the bars on the right should still look a shade stronger than those on the left.
  • Top of green, levels 240 to 255 The top sixteen levels of green, one level a bar. If the right half of the row is one flat block, green is clipped at the top and bright greens lose their detail.
  • Top of blue, levels 240 to 255 The top sixteen levels of blue, one level a bar. Blue steps are the hardest to see, so compare the two ends of the row and not neighbors.
  • Neutral grays, 16 steps from black to white Sixteen grays with red, green and blue equal, 17 levels apart from 0 to 255. Each should be a plain gray. A color cast in some bars and not others is easier to spot here than on any colored pattern.
  • Pale tints, six near-whites beside white Six near-whites, each with one or two channels lowered from 255 to 224, and pure white at the end: pale red, yellow, green, cyan, blue and magenta. Each should show a faint tint beside the white bar.

What you see and what it means 8

  • A top bar that merges with its neighbors On the top-of-range patterns the bars are one level apart. If the last few look identical, that channel is clipped at the bright end, often by a contrast setting or a vivid picture mode. One clipped channel tints the brightest whites.
  • Dark steps of a ladder that are all black The first bars of each ladder sit at levels 15, 31 and 47. If two or three of them cannot be told from black in a dim room, the shadows of that color are being crushed.
  • A tint in the grays Gray needs red, green and blue in balance. A cream, pink, green or blue cast across the row points to a night mode, a color temperature setting or a color balance setting. A cast in only the dark or only the light bars means the channels climb at different rates.
  • Colors that glow on a wide-gamut screen A wide-gamut monitor can show stronger reds and greens than the web's standard color space holds. Colors that are not managed for it are stretched to the panel's limits, so the full-strength bars look neon and over-saturated.
  • Half-strength twins that look too bright Level 128 gives about 22 percent of the light of level 255, not half, because screens follow a curve. If each twin looks only a little darker than its partner, a setting is flattening that curve and mid-tones will look washed out.
  • Two hues that look the same Orange should sit clearly between red and yellow, and violet between blue and magenta. Neighbors that match mean one channel is too strong or too weak for the others, which shifts every mixed color on the screen.
  • Pale tints that turn white Each tint differs from white by 31 levels in one or two channels. If a tint looks plain white, the top of those channels is clipped. Bright skies, snow and paper lose their faint colors the same way.
  • True color: 256 levels in each channel With 8 bits a channel a screen has 256 levels of red, green and blue, 16,777,216 colors in all. Many low-cost panels show 6 bits and mix neighboring levels to fake the rest, which can show as a fine grain in the top-of-range bars.

What to change on a computer 6

  • Turn off the night mode first A night mode warms the picture by cutting blue light. With it on, the blue ladder darkens, the grays turn cream and the pale blue tint fades. Switch it off in the display settings before you judge anything else here.
  • Look for an sRGB mode on a wide-gamut monitor sRGB is the standard color space of the web. Some wide-gamut monitors have an sRGB mode in their own menu that keeps the colors on screen inside it. If yours lists one, turn it on: the full-strength bars should lose their neon look.
  • Check which color profile the system uses The operating system keeps a color profile for each display, a description of how that screen shows color. A profile made for another monitor shifts every color. The display or color management settings name the profile in use.
  • RGB range: all three ladders cut short together When the first step of every ladder is black and all three top-of-range rows go flat at once, suspect a mismatch between full and video signal range, which trims both ends of each channel alike. The graphics driver and the monitor each have the setting.
  • A test image for a device with no browser The patterns are drawn live, but each can leave the page as a file. Press Save as PNG and pick this display's size, Full HD or 4K. Shown full screen at that exact size elsewhere, the bars carry the same color values.
  • The same ladder on two screens Open the page on both displays and show the same pattern on each. Differences the eye misses one screen at a time show up side by side: a ladder that starts later, a warmer gray, a duller hue row.

How this list was compiled: Written for this page. Every color value in the patterns was computed: ladder steps are 16 levels apart, the hues are 30 degrees apart round the color wheel at full strength, and half strength is level 128 of 255, which gives about 22 percent of the light by the formulas at https://en.wikipedia.org/wiki/SRGB. That 8 bits a channel give 256 levels and 16,777,216 colors (true color), and that many low-cost panels show 6 bits a channel and use dithering for the rest, is from https://en.wikipedia.org/wiki/Color_depth. That red and green light make yellow, green and blue cyan, and red and blue magenta is from https://en.wikipedia.org/wiki/RGB_color_model. That sRGB is the standard color space of the web is from https://en.wikipedia.org/wiki/SRGB. That every display has its own color response described by a color profile, that color management is partly the operating system's job, and that colors not tagged for it can look over-saturated on a wide-gamut display, is from https://en.wikipedia.org/wiki/Color_management. That some wide-gamut monitors have an sRGB mode in the menu that holds the colors on screen within the sRGB range, and that without one their colors are often too vivid, is from https://www.eizo.com/library/basics/lcd_monitor_color_gamut/. That video signals put black at 16 and white at 235 while a full range runs from 0 to 255 is from https://en.wikipedia.org/wiki/Rec._709. That a night mode shows warmer colors by reducing the blue light of the display is from https://en.wikipedia.org/wiki/Night_Shift_(software) and https://support.microsoft.com/en-us/windows/set-your-display-for-night-time-in-windows-18fe903a-e0a1-8326-4c68-fd23d7aaf136. All read 2026-10-02. These are drawings to judge by eye, not a calibrated reference, and nothing on the page is a measurement. Licence: own work

How it works

This monitor color test draws ladders of red, green and blue, a row of twelve hues and a row of grays across your screen. Compare neighbors: merged steps, a tint or neon colors each point to a setting.

Read the full guide

A screen color check, step by step

1. Press Go full screen. The red ladder has 16 steps, and each should look brighter than the last. 2. Click, tap or press the right arrow for green, then blue. 3. On Neutral grays, look for a tint. On the three top-of-range patterns, the last bars should still differ.

A color test pattern for monitor channels, hues and tints

The ladders show one channel alone. Color pairs sets six colors beside their half-strength twins, and Hue row runs round the color wheel in twelve steps. Pale tints puts six near-whites beside white.

  • For a monitor color test image, Save as PNG saves the pattern on show at this screen's size.
  • Turn off any night mode first: it lowers blue and warms every gray.

Questions and answers

How do I run a screen color test?

Show plain color patterns full screen and look for three things: steps that merge at the dark or bright end, a tint in the grays, and colors that look neon. This page draws the patterns, and your eyes do the judging.

Is this a color accuracy test?

By eye, yes; by measurement, no. A web page cannot see your screen. It shows known values and you compare them. Measuring color accuracy takes a device that reads colors off the glass and builds a profile from them.

Does it work as a contrast test or a brightness test?

As a contrast test, yes: on the top-of-range patterns the last bars should still differ, and on a ladder the first steps should stand clear of black. Brightness itself is light output, which no web page can measure.

Does it work as a 4K monitor color test?

Yes. Each pattern is drawn at the pixel size of the screen it is on, so the bars stay flat with clean edges at 3840 by 2160. Save as PNG offers that size too.

Why does a display color test look different on my other screen?

Every display has its own color response, and settings differ too: a night mode, a color profile, a wide-gamut panel with no sRGB mode. Open the same pattern on both screens and compare them bar by bar.

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