Color Blindness Simulator
See how colors and images look to people with different types of color blindness
Normal Vision
Normal
About the Colour Blindness Simulator
This color blind simulator shows how your colours appear to people with deuteranopia, protanopia and tritanopia alongside normal vision. It catches the most common accessibility failure, where a red-and-green status indicator collapses into two nearly identical muddy tones for around 8% of men.
A color blind simulator answers a question you cannot check by eye: does this still work for someone who does not see colour the way I do? Around 8% of men and 0.5% of women have some colour vision deficiency, which is a large share of any audience.
The three simulated types cover most of it. Deuteranopia — reduced green sensitivity — is the most common, and it is what makes red and green nearly identical. Protanopia affects red sensitivity with a similar effect on that pairing. Tritanopia, affecting blue and yellow, is rarer.
The recurring failure is meaning carried by colour alone: green for success and red for error, a red line and a green line on a chart, or required fields marked only in red. The fix is not avoiding colour but adding a second signal — an icon, a label, a different line style — so colour is reinforcement rather than the only cue.
How to use the Colour Blindness Simulator
- Enter your colours. Add the palette or the specific pair you want to check.
- Switch simulation types. Compare deuteranopia, protanopia and tritanopia against normal vision.
- Look for collapsed pairs. Find colours that become indistinguishable from each other.
- Add a second signal. Where meaning relied on colour, add an icon, label or pattern too.
Colour Blindness Simulator features
- Multiple color blindness types
- Scientific color matrix filters
- Real-time simulation preview
- WCAG accessibility testing
- Design element testing
- Color contrast analysis
- Accessibility recommendations
- Professional design tool
- Mobile-friendly interface
- Instant preview updates
Frequently asked questions
What types of color blindness does this simulator test?
Comprehensive testing for all major color vision deficiencies: Protanopia (red-blindness affecting 1% of males), Deuteranopia (green-blindness affecting 1% of males), Tritanopia (blue-blindness, rare), Achromatopsia (complete color blindness), and milder forms (Protanomaly, Deuteranomaly).
How does color blindness simulation work?
Uses scientifically-accurate color matrix transformations based on the Daltonize algorithm. Each simulation applies specific color filters that approximate how colors appear to people with different types of color vision deficiency, helping designers create accessible interfaces.
Why is color blindness testing important for web design?
Essential for WCAG accessibility compliance, reaching 8% of men and 0.5% of women with color vision deficiencies. Ensures your designs are usable by everyone, improves user experience, and meets legal accessibility requirements in many jurisdictions.
What design elements should I test for color blindness?
Test all critical interface elements: navigation buttons, form fields, error messages, status indicators, charts and graphs, data visualizations, links and interactive elements, and any color-coded information that users need to understand.
How can I make designs more color blind friendly?
Use high contrast ratios, provide text labels or icons for color-coded information, avoid relying solely on color to convey meaning, test with multiple color blindness simulators, and consider alternative visual indicators like patterns or textures.
Is this simulator accurate for real-world accessibility testing?
While not a perfect substitute for testing with actual users with color vision deficiencies, this simulator provides scientifically-based approximations that are highly effective for identifying accessibility issues during the design phase.