Color Constancy

Color constancy is the capacity of the visual system to perceive the surface color of an object as stable despite changes in the spectrum of the illuminating light. A white shirt under tungsten light reflects predominantly long wavelengths; under fluorescent light, predominantly short wavelengths. The retinal signal differs radically; the perceived color does not. The visual system solves this computationally ill-posed problem by comparing the target surface to surrounding surfaces, exploiting the statistical regularity that illuminants tend to be spatially uniform. Color constancy demonstrates that the phenomenal world is not a transmission of proximal stimulus properties but an inference about distal causes — that qualia track reconstructed physical properties, not raw sensory inputs. The phenomenon connects to broader questions in predictive processing and consciousness: if color is inferred, what aspects of experience are not?