Color Blindness Simulator
Preview how a color looks with protanopia, deuteranopia or tritanopia.
This tool runs entirely in your browser. Your files are never uploaded to a server.
Original
#e11d48
Protanopia
#8c8a3e
Deuteranopia
#98a63b
Tritanopia
#d73534
Simplified approximation of how this color may appear with common types of color vision deficiency.
What this tool does
Applies a simplified color-vision-deficiency transform to a hex color and shows the original alongside how it may appear under protanopia, deuteranopia, and tritanopia — the three most common types of color blindness.
How to use it
Pick a color with the swatch or type a hex code directly. All four preview swatches — original plus the three simulated types — update immediately, each with its own copy button for the resulting hex.
Worked example
The default color #e11d48 (a red/rose) simulates as #8c8a3e under protanopia, #98a63b under deuteranopia, and #d73534 under tritanopia — the red shifts toward olive/brown for the red-green deficiencies, while the blue-yellow deficiency leaves it comparatively close to the original since red contains little blue.
Formula
Each simulated channel is a fixed linear combination of the original R, G, and B values, using a 3×3 matrix per deficiency type (for example, protanopia: R' = 0.567R + 0.433G, G' = 0.558R + 0.442G, B' = 0.242G + 0.758B). The result is clamped to the 0–255 range per channel before being converted back to hex.
Why the result is only an approximation
These matrices are a widely used simplification that operates directly on sRGB values, rather than performing a scientifically grounded transform in LMS cone-response space with proper gamma correction — the classic, more rigorous approach used in color-science literature. That shortcut is accurate enough to illustrate the general shift in hue and saturation, but the exact simulated color can differ from a rigorous cone-based model.
Limitations
This models complete dichromacy (protanopia, deuteranopia, tritanopia) only — it doesn't cover anomalous trichromacy (protanomaly, deuteranomaly, tritanomaly), which is far more common and produces milder, partial shifts rather than a full color-channel loss. It also simulates one flat color at a time, not gradients, images, or how colors interact with surrounding context.
Scope, sources and privacy
The transform matrices are the standard simplified coefficients commonly cited for quick accessibility checks in design tooling. Everything runs locally in your browser — the color you enter is never uploaded.
Frequently Asked Questions
- What are protanopia, deuteranopia and tritanopia?
- They're the three most common types of red-green and blue-yellow color vision deficiency — protanopia and deuteranopia affect red/green perception, tritanopia affects blue/yellow.
- How accurate is this simulation?
- It's a simplified linear approximation commonly used for quick accessibility checks — not a clinically precise simulation of any individual's vision.
- How should I use this for design?
- Check that important information (like error states or chart data) isn't conveyed by color alone, and that colors remain distinguishable under each simulation.