Color appearance can be classified into two modes, the surface-color mode and the illuminant-color mode. We measured the luminance limit, defined by the luminance of the test stimulus when its appearance transitions from the surface-color mode to the illuminant-color mode, using surrounding stimuli having the distribution of luminance and chromaticity of natural surfaces. These surrounding stimuli consisted of a random pattern of overlapping circles. We aimed to determine what degree of the relationship exists between the luminance limits of colored light to appear as surface and the luminance distribution of natural surfaces. As a result, the luminance limit for the surface-color mode turned out to be similar to the upper limit of the luminance distribution of natural surfaces. Also, it shifted in the same chromatic direction as the chromaticity shift of an illuminant.
