How to Simulate Color Blindness in Your Designs
Approximately 8% of men and 0.5% of women have some form of color vision deficiency. If your design relies on color alone to convey information — red for errors, green for success — a significant portion of your users may miss it entirely. Simulating color blindness lets you catch these problems before they reach production.
- Test your designs for all types of color vision deficiency: protanopia, deuteranopia, tritanopia, and achromatopsia.
- Covers types of color blindness.
- What Breaks for Color-Blind Users.
- Covers design solutions.
- How to Test Your Designs.
Types of Color Blindness
There are three main types of color blindness, each affecting different cone cells in the retina. Protanopia (red-blind) and deuteranopia (green-blind) are the most common, both making it hard to distinguish reds from greens. They affect about 6% of men combined. Tritanopia (blue-blind) is rare, affecting blue-yellow perception. Achromatopsia (total color blindness) is extremely rare — everything appears in grayscale. Protanomaly and deuteranomaly are partial versions of protanopia and deuteranopia, where the affected colors appear muted rather than absent.
What Breaks for Color-Blind Users
Red/green status indicators with no icon or text label. Charts and graphs that use only color to distinguish data series. Form validation that shows errors only by changing the input border to red. Color-coded navigation or categories. Traffic-light color systems (red/yellow/green) without redundant indicators. Heat maps with red-green gradients. Links that are distinguished from body text only by color.
Design Solutions
Never use color as the only way to convey information. Add icons to success/error states — a checkmark for success, an X for errors. Use patterns or textures in addition to color in charts. Ensure text labels accompany color indicators. Choose color palettes that maintain sufficient contrast between colors even when simulated through CVD filters — blues and oranges are generally safe. Underline links or add an arrow icon so they're identifiable without color.
background-size animation or @property registered custom properties instead.How to Test Your Designs
Upload a screenshot or design file to the Color Blindness Simulator. Cycle through each simulation type — protanopia, deuteranopia, tritanopia, and achromatopsia. For each, ask: can I still understand every piece of information? Can I tell interactive elements from static ones? Can I read the chart legend? If anything fails, add a non-color indicator. Chrome DevTools also has a built-in CVD simulator under Rendering > Emulate vision deficiencies.
Frequently Asked Questions
How common is color blindness?
How do I test for color blindness in my design?
What colors are safe for color-blind users?
Use the Color Blindness Simulator — free, no signup required.
⚡ Open Color Blindness Simulator