Color Blindness Simulator - Test Accessibility

See how colors and images appear to people with color vision deficiencies. Simulate protanopia, deuteranopia, tritanopia, and achromatopsia. Essential for accessible design.

Normal Vision
#4f46e5
Protanopia
Red-blind (~1% of males)
rgb(75, 75, 191)
Deuteranopia
Green-blind (~1% of males)
rgb(76, 76, 181)
Tritanopia
Blue-blind (~0.01%)
rgb(79, 160, 153)
Achromatopsia
Total color blindness (~0.003%)
rgb(91, 91, 91)

About Color Vision Deficiency

Approximately 8% of males and 0.5% of females have some form of color vision deficiency. Testing your designs with a color blindness simulator ensures your content is accessible to everyone. WCAG guidelines recommend not relying on color alone to convey information.

Color Blindness Simulator for Accessible Design

Designing for color accessibility is not optional - it is a fundamental aspect of inclusive design. This simulator helps designers, developers, and content creators see exactly how their color choices appear to people with different types of color vision deficiency.

The simulation uses scientifically accurate color transformation matrices based on research by Brettel, Vienot, and Mollon. Each matrix models how specific types of cone cells in the retina respond differently, producing an accurate representation of each condition.

All processing happens locally in your browser using the Canvas API. Your images are never uploaded to any server. This makes the tool safe for testing proprietary designs and confidential materials.

How the Color Blindness Simulator Works

  1. 01Choose Color Picker mode to test a specific color, or upload an image
  2. 02View how the color or image appears under different types of color vision deficiency
  3. 03Compare Normal Vision side-by-side with simulated views
  4. 04Adjust your design to ensure accessibility across all vision types

Designing for Color Accessibility

Color vision deficiency affects approximately 8% of males and 0.5% of females worldwide. The most common types are protanopia and deuteranopia (red-green color blindness). Testing your designs with this simulator ensures that UI elements, charts, and visual content remain distinguishable for all users. WCAG 2.1 Success Criterion 1.4.1 requires that color is not the only visual means of conveying information.

When to Use the Color Blindness Simulator

Use this simulator during the design phase of any visual project: websites, mobile apps, infographics, charts, presentations, and print materials. Test before launch to catch accessibility issues early. Particularly important for data visualizations, navigation elements, and any UI where color carries meaning.

Common Use Cases

  • Testing website and app designs for WCAG color accessibility compliance
  • Verifying that charts and data visualizations are readable by colorblind users
  • Checking brand color palettes for sufficient contrast across vision types
  • Educational use: understanding how color vision deficiency affects daily life

Expert Tips

  • Always test protanopia and deuteranopia - these are by far the most common color vision deficiencies
  • Use the color picker mode for quick tests of specific hex values during development
  • Combine with the Color Contrast Checker tool for comprehensive accessibility verification

Frequently Asked Questions

How accurate is this simulation?→
The simulator uses scientifically validated color transformation matrices based on research by Brettel, Vienot, and Mollon. While no simulation can perfectly replicate individual perception (which varies even among people with the same condition), these matrices provide a reliable approximation used by accessibility professionals worldwide.
What types of color blindness are simulated?→
Four types: Protanopia (red-blind, ~1% of males), Deuteranopia (green-blind, ~1% of males), Tritanopia (blue-blind, ~0.01%), and Achromatopsia (total color blindness, ~0.003%). Protanopia and deuteranopia are the most common and most important to test for.
Are my images uploaded to a server?→
No. All image processing happens locally in your browser using the Canvas API. Your images never leave your device. This makes the tool safe for testing proprietary designs, client work, and confidential materials.
How do I make my designs more accessible?→
Never rely solely on color to convey meaning. Use patterns, icons, labels, or varying brightness in addition to color. Ensure sufficient contrast ratios (WCAG AA requires 4.5:1 for text). Test with this simulator and our Color Contrast Checker tool.

Related tools

12 suggested

From the blog

Further reading