Colour Blindness Simulator
Preview a colour as it might appear under common colour vision deficiencies.
Last updated
How to simulate colour blindness
- Pick a colour or type its code.
- See how it might look with protanopia, deuteranopia, tritanopia and achromatopsia.
About this simulation
Each variant applies a fixed transformation matrix to the colour's red/green/blue channels — a widely used simplified approximation for each deficiency type, not an exact physiological model of any individual's vision (real colour vision deficiency varies in severity and exact character from person to person). Protanopia and deuteranopia (red and green cone deficiencies) are the most common forms, affecting roughly 1 in 12 men and a much smaller share of women; tritanopia (blue) and full achromatopsia (no colour vision) are far rarer.
Nothing entered here is sent to a server — the entire simulation runs as JavaScript in your browser tab.
Questions about colour blindness
How common is colour blindness?
Red-green colour blindness affects about 1 in 12 men and 1 in 200 women. Blue-yellow (tritanopia) and total colour blindness are much rarer.
What is the difference between protanopia and deuteranopia?
Both make reds and greens hard to tell apart. In protanopia the red-sensing cones don’t work, so reds also look darker; in deuteranopia it’s the green-sensing cones.
How do I design for colour-blind users?
Don’t rely on colour alone: add labels, icons or patterns, and use colours that differ in lightness as well as hue.
Is the simulation exact?
It’s a widely used approximation. Real colour vision varies in type and severity from person to person.