Abstract
In the colorfulness adaptation effect, a scene appears desaturated after adapting to the scene rendered with high color-gamut lighting or vice versa. Previous studies have demonstrated this effect for simple stimuli and natural images on a monitor (Mizokami et al., 2012, Ilic et al., 2017). We examined whether the effect also occurs when observing a real object under real illumination. A set of objects were viewed in a light booth equipped with a spectrally tunable light. The illuminant was varied in steps from a blackbody spectrum to a wide gamut spectrum while keeping the mean illuminant color (the chromaticity for a white surface) constant. Observers chose the illuminant so that the color of the objects appeared most natural, after adapting to either the blackbody or the wide-gamut illuminant. Objects included red tomato, a blue doll, a yellow banana, and green adhesive tape. Horizontal illuminance was 150 lx on a desk where the objects were placed. Ten observers with normal color vision were tested. Adaptation to each illuminant caused the objects to appear more natural when the test illumination was shifted toward the adapting spectrum, consistent with a normalization for the adapting spectrum. Similar effects also occurred for objects viewed under real illumination. Our results suggest that color perception can rapidly adapt to changes in the color gamut produced by artificial lighting.