色の恒常性

Color constancy is a remarkable feature of human vision that compensates for the wide variations in illumination we encounter daily. A white shirt appears white whether viewed under warm incandescent light, cool fluorescent light, or blue-tinted shade. The brain achieves this by evaluating colors relative to the overall illumination context rather than in absolute terms. This adaptation is so effective that we rarely notice dramatic shifts in ambient lighting color. The famous 'dress illusion' of 2015 (#TheDress) went viral because it exposed a case where color constancy failed and people genuinely disagreed about the colors they saw.