Color Blindness Simulator — Accessibility Tester

How to Use the Color Blindness Simulator

Step-by-Step Guide

1. Choose Base Color: Click the color picker or enter a hex color code
2. Simulate: Click "Simulate Color Blindness" to generate all variants
3. Review Results: Compare how the color appears across 9 different vision types
4. Copy Colors: Click copy button on any variant to copy its hex code
5. Copy All: Click "Copy All" to copy all variants at once
6. Clear: Click "Clear" to reset and test another color

Features

Color Input

• Visual color picker for easy selection
• Manual hex code input for precise control
• Supports all valid hex color formats
• Instant simulation generation

Comprehensive Vision Types

• Normal Vision (baseline comparison)
• Protanopia (red-blind, ~1% of males)
• Deuteranopia (green-blind, ~1% of males)
• Tritanopia (blue-blind, very rare)
• Protanomaly (red-weak, ~1% of males)
• Deuteranomaly (green-weak, ~5% of males)
• Tritanomaly (blue-weak, very rare)
• Achromatopsia (complete color blindness, very rare)
• Achromatomaly (partial color blindness, very rare)

Detailed Results

• Large color swatches for easy comparison
• Prevalence information for each type
• Both HEX and RGB values
• One-click copy functionality

Copy Functionality

• Copy individual variants
• Copy all variants in a formatted list
• Instant clipboard notification
• Format: "Type: #hexcode"

Common Use Cases

Accessibility Testing

• Test color combinations for accessibility
• Ensure critical UI elements are distinguishable
• Verify error/success/warning colors work for everyone
• Check brand colors across vision types

Design System Development

• Validate color palette accessibility
• Choose colors that work for all users
• Create accessible color combinations
• Document color accessibility guidelines

UI/UX Design

• Test button states (normal, hover, disabled)
• Verify link colors are distinguishable
• Check chart and graph colors
• Validate form validation colors

Web Development

• Test website color schemes
• Verify color contrast in components
• Check notification and alert colors
• Validate data visualization colors

Understanding Color Blindness

What is Color Blindness? Color blindness (color vision deficiency) is a reduced ability to distinguish certain colors. It affects approximately 8% of males and 0.5% of females of Northern European descent. Most common types are red-green color blindness.

Types of Color Blindness:

Red-Green Color Blindness (Most Common)

• Protanopia: Cannot perceive red light. Red appears dark gray or black.
• Protanomaly: Reduced sensitivity to red light. Reds appear darker and less vibrant.
• Deuteranopia: Cannot perceive green light. Green appears beige or gray.
• Deuteranomaly: Reduced sensitivity to green light. Most common form, affects ~5% of males.

Blue-Yellow Color Blindness (Rare)

• Tritanopia: Cannot perceive blue light. Blue appears green, yellow appears violet.
• Tritanomaly: Reduced sensitivity to blue light. Blue and yellow are hard to distinguish.

Complete Color Blindness (Very Rare)

• Achromatopsia: Complete inability to see color. Vision is grayscale only.
• Achromatomaly: Partial color blindness. Very limited color perception.

How the Simulation Works: This tool uses scientifically accurate transformation matrices based on the Brettel, Viénot, and Mollon algorithm. The RGB values are transformed to simulate how the color would appear to someone with each type of color vision deficiency.

Tips for Accessible Design

1. Never Use Color Alone: Always combine color with text, icons, or patterns
2. Test Color Combinations: Use this tool to verify color pairs are distinguishable
3. Avoid Red-Green Pairs: Most common color blindness affects red and green
4. Use High Contrast: Ensure sufficient contrast between foreground and background
5. Provide Alternatives: Offer text labels, patterns, or shapes alongside color coding
6. Test Critical Elements: Always test error messages, success states, and warnings
7. Use Color Contrast Checkers: Combine with contrast ratio tools for full accessibility
8. Consider Blue-Yellow: While rare, blue-yellow color blindness should not be ignored