01
Reference vision
Original rendered sRGB pair
AB
- OKLab ΔE
- 0.260
- Separation retained
- 100%
- Pair contrast
- 1.17:1
Pair distinction lab
Can these two colors still tell different stories?
Compare a pair through three complete color-vision-deficiency simulations. Hexees measures how much perceptual separation remains and shows why labels, shapes, and icons still matter.
01 / Four views
Watch the signal change, side by side.
The same pair is transformed with severity-1 Machado matrices. The numbers describe the rendered pair; they are not accessibility grades.02
Protanopia simulation
Complete red-cone deficiency model
AB
- OKLab ΔE
- 0.124
- Separation retained
- 48%
- Pair contrast
- 1.68:1
03
Deuteranopia simulation
Complete green-cone deficiency model
AB
- OKLab ΔE
- 0.045
- Separation retained
- 17%
- Pair contrast
- 1.04:1
04
Tritanopia simulation
Complete blue-cone deficiency model
AB
- OKLab ΔE
- 0.310
- Separation retained
- 119%
- Pair contrast
- 1.16:1
A larger ΔEOK means greater computed separation in OKLab. No universal threshold proves that two colors are distinguishable for every person, display, size, border, or interface state.
02 / Redundant cues
Give meaning more than one channel.
A color pair can remain attractive and still become difficult to distinguish. Add explicit text, icons, patterns, shapes, or position so the interface does not make color carry meaning alone.
Check this pair’s WCAG text contrast →Color only
Color + text + symbol
✓ Ready! Review
03 / Method and limits
A design diagnostic, not a medical test.
Physiological simulation
The three previews use the published severity-1 linear-sRGB transformation matrices from the Machado, Oliveira, and Fernandes model.
Machado, Oliveira & Fernandes, 2009Perceptual separation
Hexees reports Euclidean ΔEOK in OKLab and the standard relative-luminance contrast ratio for each simulated sRGB pair.
CSS Color 4 · ΔEOKUse color responsibly
The preview is not a diagnosis and does not certify WCAG conformance. Test the complete component and preserve a visible cue that does not rely on color.
WCAG 2.2 · Use of Color