One pair of colours, blended in four spaces
Drawn at its defaults, in gamut and chromaticity.
It reads 6 options and
no others: show, obs, steps, from, to, spaces.
Called by 2 essays
the blast radius of changing it
A gradient is a path
Two colours fix the ends of a blend and nothing else. The middle is decided by the space the interpolation happens in, and four spaces in daily use put the halfway point of one ordinary gradient as much as thirty-seven units of colour difference apart.
Matching and measuringThe mixture line bows
Grassmann's second law says an additive mixture is exactly linear in tristimulus values, and tested here it is exact to floating point. Nothing downstream of the three numbers preserves it. The physical half-and-half mixture of two colours sits a median of 5.5 colour differences from the midpoint of their two readings and up to thirty; on a green and a blue display primary it is twenty-one, which is a quarter of the distance between them.