Color Blindness Simulator
Enter any color and see how it looks to people with common types of color vision deficiency. About 1 in 12 men sees color differently — check your palette before you ship.
Test a whole palette
Eight colors designers reach for most — each simulated at the severity above.
Sample UI under each vision type
Tip: red error badges and green success badges are the classic failure — try the preset colors above on your own palette.
How the simulation works
Color vision deficiency is simulated by multiplying each color's RGB channels by a published 3×3 transformation matrix — the standard simplified model from Machado, Oliveira & Fernandes (2009), “A Physiologically-based Model for Simulation of Color Vision Deficiency” (IEEE TVCG). Each matrix redistributes color information to approximate the loss of one cone type. Outputs are clamped to valid RGB ranges; achromatopsia is rendered by luminance (0.299R + 0.587G + 0.114B).
This is an educational approximation used by most lightweight simulators, not a clinical model. It cannot diagnose color vision deficiency.
Types of color vision deficiency
| Type | Missing cones | Effect | Approx. prevalence |
|---|---|---|---|
| Protanopia | L (red) | Reds look dark; red–green confusion | ~1.0% of men |
| Deuteranopia | M (green) | Red–green confusion; greens shift yellowish | ~1.1% of men |
| Tritanopia | S (blue) | Blue–yellow confusion | ~0.002% of men (very rare) |
| Achromatopsia | All | Total color blindness; luminance only | ~1 in 33,000 |
Prevalence figures are commonly cited estimates for full dichromacy; milder “anomaly” forms are more common.
Designing for color-blind users
- Never communicate by color alone — pair status colors with icons or text labels.
- Check that your error red still reads as “wrong” under deuteranopia (it often doesn't).
- For charts, prefer blue–orange or blue–red pairs over red–green.
- Run your palette through this simulator at 100% severity before shipping.
FAQ
How is color blindness simulated?
Each color's RGB channels are transformed by a published 3×3 matrix (Machado, Oliveira & Fernandes, 2009) approximating how the remaining cone types respond. It's the standard simplified model most educational simulators use — good for design checks, not clinical diagnosis.
What is the most common type of color blindness?
Red–green deficiency (protanopia / deuteranopia) — roughly 1 in 12 men and 1 in 200 women have some form. Blue–yellow deficiency (tritanopia) is extremely rare.
Is this simulator medically accurate?
No. It's a mathematical approximation for checking designs. If you suspect you have color vision deficiency, see an eye-care professional.
Why should designers simulate color blindness?
About 300 million people worldwide have some color vision deficiency. Simulating your palette catches charts, badges, and error states that rely on color alone — then you can add a second cue like an icon or label.
Is my color data uploaded anywhere?
No. Everything runs locally in your browser; no colors, no analytics, no tracking.