What percentage of people are color blind?

About 8% of men and 0.5% of women have some form of color vision deficiency. The most common types are red-green (protanopia and deuteranopia), affecting roughly 1 in 12 men.

How do I make my designs accessible for color blind users?

Never rely on color alone to convey information. Use shapes, patterns, labels, or icons alongside color. Test with a simulator like this to verify your designs remain clear under all deficiency types.

What is the difference between protanopia and deuteranopia?

Both are red-green color blindness. Protanopia reduces sensitivity to red light, making reds appear darker. Deuteranopia reduces sensitivity to green light. Both make red and green hard to distinguish, but in slightly different ways.

Adjustments

Color Blindness Simulation

Simulate how images appear to people with different types of color vision deficiency, including protanopia, deuteranopia, tritanopia, and achromatopsia. Essential for accessibility testing of UI designs, infographics, and data visualizations.

Deploy with Docker View Source

Features

Simulates 8 types of color vision deficiency
Protanopia, deuteranopia, tritanopia, and achromatopsia
Side-by-side comparison with original
Batch test across multiple screenshots
WCAG accessibility context for each deficiency type

What you can do

Test UI designs for accessibility before shipping to production
Verify data visualizations are readable for color-blind users
Check that color-coded maps and charts remain distinguishable
Audit marketing materials for inclusive color usage

Self-hosted. Your files never leave your network.

SnapOtter runs entirely on your own infrastructure. Files processed with Color Blindness Simulation are never uploaded to third-party servers. Deploy a single Docker container and process files with full privacy, no watermarks, and no usage limits. Open source under AGPL-3.0.

Frequently asked questions

What percentage of people are color blind?: About 8% of men and 0.5% of women have some form of color vision deficiency. The most common types are red-green (protanopia and deuteranopia), affecting roughly 1 in 12 men.
How do I make my designs accessible for color blind users?: Never rely on color alone to convey information. Use shapes, patterns, labels, or icons alongside color. Test with a simulator like this to verify your designs remain clear under all deficiency types.
What is the difference between protanopia and deuteranopia?: Both are red-green color blindness. Protanopia reduces sensitivity to red light, making reds appear darker. Deuteranopia reduces sensitivity to green light. Both make red and green hard to distinguish, but in slightly different ways.

More Adjustments tools

Adjust Colors

Brightness, contrast, exposure, saturation, temperature, sharpness, and effects

Learn more Sharpening

Adaptive, unsharp mask, and high-pass sharpening with presets

Learn more Replace & Invert Color

Replace specific colors or invert

Learn more Duotone

Apply a two-color duotone effect with custom shadow and highlight colors

Learn more

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