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

The same gradient blended two ways

Above, the code values are interpolated, which is what most tools do. Below, the luminances are. The midpoint of the top ramp carries 23 per cent of white's luminance where it should carry 51, so the top ramp is visibly too dark through its middle.
The same gradient blended two ways. Above, the code values are interpolated, which is what most tools do. Below, the luminances are. The midpoint of the top ramp carries 23 per cent of white's luminance where it should carry 51, so the top ramp is visibly too dark through its middle.

Drawn at its defaults, in displays and encodings. It reads 3 options and no others: from, to, steps.

Called by 2 essays

the blast radius of changing it

Difference and uniformity

The midpoint is not half

Code 128 sits halfway along the sRGB scale and carries about a fifth of white's luminance. Half the luminance is code 188. Almost every gradient, blur and resize on the web gets this wrong, and the errors are visible once known.

 What a scene does

A mixture in the variable nobody named

Kubelka–Munk works because absorption and scattering add over a mixture and reflectance does not. What adds is the absorption of the pigment layer, and what an instrument reports is that layer seen through an interface — related by a Möbius function rather than by a constant. Mixing in the reported variable instead of the internal one costs between three and eight ΔE₀₀, and no source this collection quotes says which variable its curves are in.

All 155 generators · what each essay asks for instead