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

Where the model breaks

Seventeen observers in 1931, an error in the blue that was never fully repaired, colour vision deficiency, and the display this page is being read on.
400450500550600650700wavelength / nmx̄ȳz̄ȳ is the luminous efficiency functionCIE 1931 2° observer

Seventeen observers in 1931

The standard observer that governs every colour specification in industrial use is an average over seventeen young British men, measured with equipment from the 1920s. It is known to be wrong in the blue, the correction has existed since 1951, and it has never been adopted.

 normal trichromatprotanopiadeuteranopiatritanopiaBrettel–Viénot–Mollon 1997, severity 1.0a simulation is not an experiencesRGB, D65

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.

 one rectangle, or two?a visible seam means the display reaches past sRGBevaluated by the browser, not the buildCSS color(display-p3 …)

The display is an unknown

This site is displayed on the very apparatus it is about, and it knows almost nothing about that apparatus. Two figures here stop assuming and ask instead — a probe for the transfer function and a probe for the gamut.

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