Why you need a color blindness palette fixer
Roughly 1 in 12 men and 1 in 200 women have some form of color vision deficiency (CVD), so any palette you ship will be misread by a meaningful slice of your audience. The color blindness palette fixer on this page lets you preview every swatch through eight different CVD models and then auto-rebuild the palette into a version that stays distinguishable for everyone — without throwing away your brand identity.
Color blindness isn't a single condition. Color is a known accessibility barrier under WCAG, and the most common forms — deuteranomaly (green-weak) and protanomaly (red-weak) — make red, orange, brown, and green nearly impossible to tell apart. Pink–turquoise–grey and purple–blue combinations are also high-risk pairings that need testing before launch.
How the daltonization works
Under the hood, the tool follows the same matrix-based approach used by mainstream open-source libraries: colors are converted from sRGB into LMS cone space, transformed with the Brettel–Viennot model to mimic the missing cone response, and projected back to RGB. The error between the original and the simulated color is then redistributed across channels — a process known as daltonization — so confusable pairs become visually distinct.
The eight simulations covered are:
- Protanopia and protanomaly — red-blind / red-weak
- Deuteranopia and deuteranomaly — green-blind / green-weak (the most common form)
- Tritanopia and tritanomaly — blue-blind / blue-weak
- Achromatopsia and achromatomaly — full or partial loss of color vision
A complete accessibility workflow
Run the fixer early, then chain it into the rest of your accessibility pipeline. Build the palette in the color safe palette builder, fix the swatches here, and then verify text and UI pairings with the palette contrast grid to confirm AA and AAA compliance. If you want a deeper before/after view of a single hue, the color blindness simulator shows pixel-level changes.
Best practices that go beyond color
- Never rely on color alone — back it up with icons, labels, or patterns.
- Favor blue/orange or blue/red combinations; they survive almost every CVD profile.
- Avoid red/green status indicators; swap to blue/orange or add shape cues.
- Re-test charts and data viz, where adjacent categorical colors collide most often.
When you're satisfied, export the corrected palette as HEX, RGB, CSS custom properties, or design tokens and drop it straight into your codebase. Ship a palette that works for every viewer — not just the ones with average cone cells.
]]>