Screen colour test

What to look for

• Tint across the screen: on plain grey or white, one side looking warmer or cooler than the other shows uneven colour or backlight.
• Primary colours: red, green and blue should each look clean and even. A stuck sub-pixel stands out as a dot of a different colour; for a guided check use the dead pixel test.
• Banding or blotches on a flat colour, especially grey, point to panel uniformity issues or aggressive picture processing.
• Colour accuracy: comparing two screens side by side with the same colour shows which one is tinted. This is a visual comparison, not a calibration.

Dedicated colour pages

For the most common uses there are single-colour pages with suitable shades: a white screen for light and cleaning, a black screen for backlight bleed, a red screen for night use, and a pink screen as a soft fill light.

Screen turned blue, purple or pink on its own?

If your display shows a colour tint you did not choose, that is a fault, not a setting this page can fix. On computers, a full blue screen with text is a system crash (often called the blue screen of death). On phones and laptops, a purple or pink cast across the whole picture usually points to a damaged display, a loose display cable or a graphics driver problem. Note when it happens and contact the manufacturer or a repair service; showing a solid colour here helps you see whether the tint covers the whole panel.

Limits

The page sends exact RGB values, but what you see also depends on the screen's colour mode, night-light filter, HDR settings and brightness. It does not measure colour or brightness; that needs a colorimeter.