Color Accuracy Test

What this page can and cannot do

A screen cannot check its own colors: it shows you the same colors it is producing, so a display with a strong blue cast shows that cast on every patch, including the ones meant to judge it. What these patches give you is an exact, labeled starting point. Each one is a standard sRGB value, so two screens showing this page can be compared directly, and an obvious cast or a flat, dull primary becomes easier to notice.

1. 1

   Open the patches full screen and turn off night mode, blue-light filters and any automatic color adjustment.

2. 2

   Compare two screens side by side with the same page open, in the same room light.

3. 3

   Watch the grays. White and the three grays make a color cast easiest to see; they should look neutral, not pink, green or blue.

4. 4

   Try the display's color presets, such as sRGB or Standard, and compare again.

What an obvious problem looks like

A color cast tints the grays and white toward one color across the whole screen. Dull primaries make red, green and blue look muted, which can simply mean the panel covers less of the color range. Oversaturation does the opposite: colors look strong and slightly unreal, often because a vivid picture mode is on. Any of these can be changed in the display's picture settings.

If you need real accuracy

Measuring color needs a hardware sensor, called a colorimeter, placed against the screen. It reads what the panel actually emits and builds a correction profile. Nothing shown in a browser can replace that, and photos of a screen are even less reliable, because the camera applies its own processing.

For the tone curve between black and white, use the Gamma Test; for smooth ramps and banding, the Color Banding / Gradient Test. How to Calibrate a Monitor explains where adjusting by eye stops and a measuring device takes over.