Saturation contrast — pure vs. diluted color — can be achieved by mixing with white, black, gray, or the complementary

Saturation (also called ‘quality’ or purity) is the degree to which a color is unmixed. Pure prismatic hues are maximum saturation. A color can be diluted in four distinct ways, each with different results: (1) adding white — cools the hue and reduces intensity; carmine becomes bluish, yellow cools; (2) adding black — removes luminosity and character; yellow becomes poisonous/sickly, violet deepens toward night; (3) adding gray (white+black) — dulls without the character-shifts of pure white or black; (4) mixing the complementary — produces chromatic grays, mixtures with full-spectrum character rather than the dead quality of achromatic gray. Saturation contrast is the contrast between a vivid and a dulled version of a hue — or between a vivid hue and neutral gray at the same brilliance. The dull/gray areas ‘live’ by virtue of the vivid ones around them: isolated gray appears dead; gray surrounded by vivid colors appears to glow with a borrowed hue.

Examples

Shader: float sat = smoothstep(0.0, 1.0, audio_rms); vec3 col = mix(gray, pure_hue, sat); — audio drives saturation from gray to full vivid. Hydra: src(s0).saturate(map(amplitude,0,1,0,2)).

Assessment

Describe what happens to yellow when you add black vs. white; explain why mixing complementaries produces a richer gray than mixing with achromatic gray; design a saturation-contrast exercise eliminating all other contrasts.