Generator
A constant-lightness hue circle at chroma 0.13, with the unreachable arcs hatched
Thirty-six hues at one lightness and one chroma. 33 of 36 are inside the sRGB gamut; the rest are hatched. The gaps are not evenly spaced, because the gamut is a triangle in a space where a constant-chroma circle is a circle.
Drawn at its defaults, in gamut and chromaticity. It takes no options at all, so every essay calling it gets this exact drawing.
Called by 2 essays
the blast radius of changing it
Matching and measuring
A hex code is not a colour
Six hexadecimal digits identify three numbers. Turning three numbers into a colour needs a colour space, a transfer function, a white point and a display, and leaving any of them unstated is the everyday version of every confusion in colour management.
What a camera doesA blown highlight turns
An exposure that clips nothing changes no hue at all. Once one channel reaches the ceiling the recorded hue rotates by as much as sixty-seven degrees, with nothing in the scene having changed colour — and every response a converter can make to that is an invention.