Colorblind Differentiation Score
Quantify how distinguishable your colors are for people with different types of color blindness using Delta E in CIELAB color space
Colorblind Differentiation Score
Quantifies how distinguishable your colors are for people with different types of color vision deficiency. Uses Delta E (CIE76) on simulated colors.
Quick Presets
Colors to Test (5/10)
Original vs Simulated
Your colors are well differentiated for most colorblind users.
Weighted: Protanopia 35% + Deuteranopia 35% + Tritanopia 15% + Achromatopsia 15%
Score Interpretation
Based on Delta E (ΔE) color difference in CIELAB space. ΔE < 5 is barely noticeable, ΔE > 20 is clearly different.
Tips for Colorblind-Safe Design
- • Avoid red-green combinations — the most common issue (8% of males)
- • Use high luminosity contrast between adjacent colors
- • Add patterns, icons, or text labels as secondary indicators
- • Use blue-orange or blue-yellow as safe alternatives to red-green
- • In charts, combine color with shape (circles, squares, triangles)
- • Test with real users when possible
How it works
Colorblind color differentiation goes beyond simple simulation. This tool numerically quantifies whether your colors are sufficiently distinguishable for people with color vision deficiency, using the Delta E (CIE76) metric in CIELAB color space.
Tool features
Quick presets
6 predefined palettes: problematic and safe ones for instant testing.
Visual comparison
Original vs simulated side-by-side for all 4 types of color blindness.
Pairwise ΔE matrix
Detailed table showing the distance between each color pair.
Copyable report
Copy complete results with one click for documentation.
Types of color blindness analyzed
- Protanopia: Red-blindness (~1% of males). L-cones (long wavelength) don't function. Weight in score: 35%.
- Deuteranopia: Green-blindness (~6% of males). M-cones (medium wavelength) don't function. Weight: 35%.
- Tritanopia: Blue-blindness (~0.01% of population). S-cones (short wavelength) don't function. Weight: 15%.
- Achromatopsia: Complete color blindness (very rare). Only luminance is perceived. Weight: 15%.
What is Delta E (ΔE)?
Delta E is a metric defined by the CIE (Commission Internationale de l'Éclairage) that measures the perceptual difference between two colors in CIELAB color space. We use the CIE76formula (Euclidean distance in L*a*b*):
- ΔE < 1: Imperceptible to the human eye
- ΔE 1-2: Barely perceptible under ideal conditions
- ΔE 2-5: Perceptible with attention
- ΔE 5-10: Clearly different at a glance
- ΔE 10-25: Very different colors
- ΔE > 25: Completely distinct colors
Score interpretation
The score (0-100) is based on the minimum ΔE between all pairs of simulated colors, because the most difficult pair determines overall accessibility:
- 70-100: Safe — Colors are clearly distinguishable even for colorblind users
- 40-69: Caution — Some pairs may be confused, check the matrix
- 0-39: Danger — Multiple colors are indistinguishable, needs changes
Inclusive design tips
- Avoid red-green combinations (affects 8% of males)
- Use blue-orange or blue-yellow as safe alternatives
- Ensure high luminosity contrast (L* in CIELAB) between adjacent colors
- Add patterns, icons, or text as secondary indicators
- In data charts, combine color + shape (circles, squares, triangles)
- Test with real users when possible
Practical examples
Case 1: Bar chart with 5 categories
You have a chart with colors: #FF6B6B, #4ECDC4, #45B7D1, #96CEB4, #FFEAA7
→ Deuteranopia Score: 45 — Red and green are confused
→ Solution: Change green to dark blue → Score: 78
Case 2: Form validation states
You use red for error and green for success in field validation.
→ Protanopia Score: 28 — Almost indistinguishable
→ Solution: Add icons in addition to color, or use orange + blue
Case 3: Heat map
Your map uses a green-to-red gradient to show values.
→ Overall Score: 35 — Problematic for 8% of men
→ Solution: Blue-yellow gradient + numeric labels → Score: 85