Colour Science & Perception
what the eye settles, and what it cannot
Generator

One palette under normal vision and three dichromacies

The same 7 colours simulated by the Brettel–Viénot–Mollon construction at severity 1.0. protanopia and deuteranopia collapse the red-green distinctions, and tritanopia leaves them and collapses blue against yellow instead. This shows which discriminations survive, not what anybody sees.
One palette under normal vision and three dichromaciesThe same 7 colours simulated by the Brettel–Viénot–Mollon construction at severity 1.0. protanopia and deuteranopia collapse the red-green distinctions, and tritanopia leaves them and collapses blue against yellow instead. This shows which discriminations survive, not what anybody sees.normal trichromatprotanopiadeuteranopiatritanopiaBrettel–Viénot–Mollon 1997, severity 1.0a simulation is not an experiencesRGB, D65

Drawn at its defaults, in colour vision, and its variants. It takes no options at all, so every essay calling it gets this exact drawing.

Called by 3 essays

the blast radius of changing it

Where the model breaks

Simulating what cannot be simulated

A colour-blindness simulation cannot show what anybody sees. What it can show is which discriminations survive, and that is a narrower claim, a checkable one, and the only one worth making.

 What the eye does

Three cones, two axes

The retina does not send three receptor signals down the optic nerve. It sends a sum and two differences, and the reason falls out of the statistics of natural light rather than out of anything the eye intended.

 Where the model breaks

There is no word for that colour

The naming model built this phase gives a saturated cyan the name green, calls part of a chromatic ring grey, and puts one of the eleven focal colours outside what a display can show. Each failure is a measurement rather than a disclaimer, and together they say what a vocabulary is that eleven points and a distance are not.

All 155 generators · what each essay asks for instead