A grid of reference patches is lit by a tinted illuminant: each true RGB reflectance is multiplied by the illuminant's own RGB (0–1). Von Kries adaptation undoes this by dividing each channel back out, blended by the Adaptation Strength slider — at 1.0 the illuminant's multiplicative tint is fully cancelled, recovering the patch's true reflectance.
lit = reflectance × illuminant
vonKries = mix(lit, lit / illuminant, strength)
Retinex: L_c(x) = I_c(x) / max_scene I_c → illuminant cancels
Retinex mode shows that a scene-wide multiplicative illuminant change (e.g. ×1.25 on R) shifts every raw channel, but each channel divided by its own scene maximum is identical under both lights — color is a ratio of reflectances, not an absolute intensity. The Dress mode divides the same ambiguous pixel by two different assumed illuminants (a bright warm one vs. a dim cool one), producing the two competing percepts.