Color Blindness Simulator
See how your colors look to the 300 million people with color vision deficiency.
Three steps
How to use it
-
1
Add your colors
One color, or a whole palette pasted as a list of hex codes.
-
2
Compare the simulations
Deuteranopia and protanopia are the red-green types and account for the large majority of cases. Tritanopia affects blue-yellow and is far rarer.
-
3
Look for collapses
The thing to watch for is two colors in your palette becoming the same color in a simulation. That is where meaning gets lost.
About this tool
The simulations use the Brettel-Viénot-Mollon method, which projects colors onto the plane a dichromatic viewer can actually distinguish. They are approximations of a subjective experience, nobody with normal color vision can see exactly what a dichromat sees, but they are reliable for the question that matters: do these two colors still look different?
The practical rule this leads to is simple and does not require a simulator to apply: never encode meaning in hue alone. A red error state and a green success state that differ only in color are indistinguishable to a large minority of users. Add an icon, a label, or a difference in lightness, and the problem disappears for everyone.