39 / Colour

Gamut Arc

Two ways to get from terra to blue. The left field goes round the outside and is a full colour the whole way; the right one goes straight across and turns to mud halfway.

also called hue path · chroma preservation · colour interpolation

How much colour a screen can hold changes with hue: the space bulges towards violet and pinches near cyan, so it is not a cylinder. That makes the route between two colours a gamut question rather than a matter of taste — and the default route, a straight line through the middle of the space, is the one that passes closest to grey. The strips under each field are the whole journey at once.

How it is built

/* round the outside */ background: oklch(0.637 0.148 calc(40.2deg + var(--t) * -135.8deg)); /* straight across — what you get by default */ background: color-mix(in srgb, <end> calc(var(--t) * 100%), <start>);