Bezold-Brücke shift

The Bezold-Brücke shift is a change in hue perception as intensity changes. As intensity increases, spectral colors shift more towards blue (if below 500nm) or yellow (if above 500nm). At lower intensities, the red/green axis dominates. See especially Opponent process.

This effect is a problem for HSV-style theories of color, which treat hue and intensity as independent parameters.

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 * Purkinje shift