Color Vision Simulator
Preview how a sample palette appears under different color vision conditions.
Tip: never rely on color alone — always pair color with a label, icon, or text cue.
About This Tool
The Color Vision Simulator transforms a sample color palette to show how it appears under different color vision deficiency conditions. Approximately 1 in 12 men (8%) and 1 in 200 women (0.5%) have some form of color vision deficiency, making this tool essential for designers, marketers, and content creators who want to ensure their color choices are universally distinguishable.
The tool simulates four conditions: Protanopia (red-blind), Deuteranopia (green-blind, the most common form), Tritanopia (blue-blind, very rare), and Achromatopsia (complete color blindness, seeing only grayscale). By switching between these modes, you can verify that your color-coded information remains clear and distinguishable to all users.
Tool Guide
Select a condition
Choose from Normal vision, Protanopia, Deuteranopia, Tritanopia, or Grayscale using the dropdown menu.
Observe the palette
The five-color palette instantly transforms to show how each color is perceived under the selected condition.
Compare conditions
Switch between conditions to see which colors become indistinguishable. Look for colors that merge into the same shade — that's a problem.
Fix accessibility issues
If two colors look identical under a deficiency, add text labels, icons, or patterns to differentiate them — never rely on color alone.
How to Use
- Deuteranopia is most common: About 6% of men have deuteranopia or deuteranomaly. Always check this mode first — if your design works here, it likely works for most color-blind users.
- Red-Green conflation: Red and green are the most commonly confused colors. If your design uses red/green to indicate error/success, add icons (✓/✗) or text labels as well.
- Tritanopia is rare but important: Blue-yellow deficiencies affect less than 0.01% of the population but can still occur from aging, diabetes, or eye injury.
- Grayscale testing: The grayscale mode simulates complete color blindness. If your design is readable in grayscale, it will work for virtually all users.
- Beyond color: Always pair color with redundant cues — text labels, icons, patterns, or spatial positioning. This ensures accessibility even if colors fail entirely.
Frequently Asked Questions
Is this an accurate simulation of what color-blind people see?
This tool uses mathematical color transformation models (Brettel-Viénot-Mollon algorithm) to approximate how colors appear under each condition. It is a close approximation, but individual experiences vary. Some color-blind individuals may see more nuance or different shifts than the simulation shows.
What's the difference between Protanopia and Deuteranopia?
Protanopia is the absence of red cone cells (L-cones), making red appear darker. Deuteranopia is the absence of green cone cells (M-cones), which is the most common type. Both fall under "red-green color blindness" but affect color perception differently.
Can I test my own color palette instead of the default one?
This version of the tool uses a fixed sample palette (Red, Green, Blue, Yellow, Purple). These colors represent common UI color choices and help you quickly identify which hues cause problems for different vision conditions.
What is achromatopsia (grayscale)?
Achromatopsia is a rare condition (affecting ~1 in 33,000 people) where all color perception is absent. The grayscale mode converts all colors to luminance values, showing how your design appears without any color information at all.
My design looks fine in grayscale. Do I still need to check other modes?
Grayscale is the most extreme condition. If your design works in grayscale, you've likely solved the luminance contrast issue. However, checking individual modes like Deuteranopia helps verify that color-specific cues (like red error messages) don't cause confusion.
Does color blindness affect men and women equally?
No. Red-green color deficiencies (Protanopia and Deuteranopia) are X-linked recessive traits, affecting approximately 8% of men but less than 0.5% of women. Blue-yellow deficiencies (Tritanopia) are not sex-linked and affect men and women equally.