Tinta Color blindness simulator
See a palette the way people with each common color vision deficiency see it, and find the colors that stop being distinguishable.
Color 1 · Crimson
Color 2 · Sea Green
Color 3 · Khaki
Color 4 · Charcoal Blue
Tip: paste a list of hex codes anywhere here to check them all at once.
Color blindness check
About 1 in 12 men and 1 in 200 women see color differently. Simulated with the Machado (2009) model.
No green cones — the most common form. Crimson, #D72638 and Sea Green, #2E8B57 become hard to tell apart — don't rely on color alone to separate them.
Who sees color differently
About 1 in 12 men and 1 in 200 women have a color vision deficiency. The most common forms are red-green: deuteranopia (missing or weak green cones) and protanopia (missing or weak red cones), where reds, greens, browns and oranges collapse toward similar olive and mustard tones. Tritanopia, a blue-yellow deficiency, is rare and confuses blues with greens and yellows with pinks. Achromatopsia, seeing no color at all, is rarer still, but its grayscale view is a useful test for anyone: if two colors match in grayscale, they match in lightness.
How the simulation works
Each color is converted to linear light and multiplied by the matrices from Machado, Oliveira and Fernandes (2009), the model most accessibility tools use for full-strength deficiencies. The simulator then compares every pair and flags the ones that are distinct to typical vision but become hard to tell apart.
Designing for it
Never let color be the only signal. Pair a red error state with an icon and text, label chart series directly instead of relying on a legend, and give links an underline. When two palette colors clash in the simulation, separate them in lightness rather than hue: a light and a dark color stay distinct for every kind of vision. The contrast checker shows lightness differences as a ratio, and every palette on Tinta has this same check on its page.