Colour Blindness Simulator
See how a list of colours looks with protanopia, deuteranopia, tritanopia and achromatopsia, to check that status colours and chart series stay distinguishable.
Free · No sign-up · Your inputs stay in your browser
Input
Simulate colour blindness on a palette
Output
5 colours
| Label | normal | protanopia | deuteranopia | tritanopia | achromatopsia |
|---|---|---|---|---|---|
| ok | #16a34a | #a49442 | #958951 | #00a08f | #8e8e8e |
| error | #dc2626 | #635923 | #8f801b | #f3002a | #727272 |
| warning | #ea580c | #837300 | #a79400 | #ff2e4c | #888888 |
| info | #2563eb | #0076f0 | #0064e8 | #00869d | #6d6d6d |
| accent | #9333ea | #0069ef | #006ae6 | #80658f | #6a6a6a |
Protanopia and deuteranopia (no red or green cones) affect about 1 in 12 men and 1 in 200 women of Northern European descent; tritanopia is rare. Simulated with Machado, Oliveira and Fernandes' 2009 model at full severity, in linear RGB. The usual failure is a red/green status pair: give every state an icon or a word as well as a colour, which WCAG 1.4.1 requires.
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About this tool
Method, assumptions, practical next steps, and limits.
Who is affected
Red-green colour vision deficiency affects about 1 in 12 men and 1 in 200 women of Northern European descent. The classic failure is a red error and green success state that look the same; charts with red and green series fail the same way.
Do not rely on colour alone
WCAG's Use of Color criterion requires that information conveyed by colour is also available another way: an icon, a label, a pattern or a position. Simulation helps choose colours that stay distinct, but the second cue is what makes the interface work.