Color Blindness Simulator
Enter up to 8 hex colors from your design and see how they appear to people with each type of color vision deficiency. Click any swatch to copy its simulated hex.
Normal vision
~92% of all people
Deuteranomaly
~5% of males
Deuteranopia
~1% of males
Protanomaly
~1% of males
Protanopia
~1% of males
Tritanomaly
Very rare (< 0.01%)
Tritanopia
Very rare (< 0.01%)
Achromatopsia
~0.003% of people
Achromatomaly
Extremely rare
Click any swatch to copy its hex code. Simulation uses Machado et al. 2009 matrices in linear-light RGB space.
Types of Color Blindness
| Type | What happens | Prevalence |
|---|---|---|
| Deuteranomaly | Reduced green sensitivity — the most common type of color blindness. | ~5% of males |
| Deuteranopia | No green cone cells — reds and greens look very similar. | ~1% of males |
| Protanomaly | Reduced red sensitivity — reds appear darker and duller. | ~1% of males |
| Protanopia | No red cone cells — reds appear dark, greens and reds are confused. | ~1% of males |
| Tritanomaly | Reduced blue sensitivity. | Very rare (< 0.01%) |
| Tritanopia | No blue cone cells — blues appear green, yellows appear violet. | Very rare (< 0.01%) |
| Achromatopsia | Complete color blindness — only shades of grey are visible. | ~0.003% of people |
| Achromatomaly | Partial achromatopsia — very limited, muted color perception. | Extremely rare |
Designing for Color Accessibility
Don't rely on color alone
Add shape, pattern, or text labels to distinguish elements. A red/green status system fails for ~8% of male users — a checkmark/cross icon doesn't.
Check contrast ratios too
WCAG AA requires 4.5:1 for normal text and 3:1 for large text. High contrast helps everyone, including users with low vision.
Use perceptually distinct colors
Blue and orange, or blue and red, remain distinguishable for most types of color blindness — unlike red/green pairs.
Test with real users
Simulation is a starting point. If your product is critical for users with color blindness, test with real people in addition to automated tools.
Frequently Asked Questions
What is color blindness?
Color blindness (color vision deficiency) is the reduced ability to distinguish certain colors, caused by absent or abnormal cone cells in the eye. About 8% of males and 0.5% of females have some form of color blindness. The most common types — deuteranomaly and protanomaly — involve reduced sensitivity to green or red light respectively, while rarer types like tritanopia affect blue perception. Complete color blindness (achromatopsia) is extremely rare.
Why does color blindness matter for designers?
WCAG 1.4.1 (Use of Color) requires that color is not the only visual means of conveying information. If two important colors in your design appear identical to a color-blind user, they cannot distinguish them regardless of contrast ratio. Simulating your palette before shipping helps you catch these issues early — for example, switching from a red/green status system to shapes or labels in addition to color.
What types of color blindness does this tool simulate?
This tool simulates all 9 clinically recognized categories: Normal vision (baseline), Deuteranomaly (most common — reduced green), Deuteranopia (no green cones), Protanomaly (reduced red), Protanopia (no red cones), Tritanomaly (reduced blue), Tritanopia (no blue cones), Achromatopsia (complete grayscale), and Achromatomaly (partial achromatopsia). Together these cover the full spectrum of inherited color vision deficiency.
How accurate is the simulation?
This simulator uses the Machado et al. 2009 matrices, applied in linear-light RGB space with proper sRGB gamma correction. These are the industry-standard matrices used by professional color tools and are significantly more accurate than naive sRGB-space approximations. The simulation is a perceptual model — it shows what colors are likely to be confused, not an exact pixel-perfect rendering of what any individual sees, since color blindness varies in severity from person to person.
My palette looks fine under simulation — is it accessible?
Passing the color blindness simulation is a good sign, but not the complete picture. You should also check contrast ratios (WCAG AA requires 4.5:1 for normal text, 3:1 for large text) and ensure color is not the only differentiator for important information. Use the Contrast Checker tool on Colortion to verify contrast ratios alongside this simulator.