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Accessibility · vision preview

Color blindness simulator

Compare an original color against eight common color-vision simulations (protanopia, deuteranopia, tritanopia, and anomaly variants). Use it before you rely on red/green alone for errors, success, or chart series.

Why this tool exists

WCAG contrast ratios do not catch confusing hue pairs for color-blind users. Simulation is imperfect but catches obvious “red vs green” KPI lines that collapse into mud brown.

How to use it

  1. Pick a color with the native input or paste from your design system.
  2. Cycle vision types in the dropdown — compare side-by-side panels.
  3. Note which pairs become indistinguishable and add icons, labels, or patterns.
  4. Pair with the contrast checker for luminance, not just hue.

Use a different tool when…

You need medical diagnosis or compliance certification — this is a design aid, not clinical software.

Practical tips

  • Simulations approximate sRGB matrices; they vary slightly by tool and display.
  • Test charts with patterns, not only color swaps.
  • Achromatopsia preview is rare but useful for checking reliance on hue alone.

FAQ

Which type should I test first?

Deuteranopia and protanopia cover most red-green confusion cases in UI.

Is this accurate for all displays?

It models sRGB. OLED, HDR, and uncalibrated monitors still shift perception.

Can I simulate entire screenshots?

This page is per-color. For full UI, test in browser extensions or design plugins too.

Do simulations satisfy legal requirements?

They help design; legal compliance still needs process, audits, and user testing.

Why eight types?

Covers common CVD categories cited in accessibility literature and design tooling.