Abstract
Metallic colors, such as gold, silver and bronze colors, appear on a surface depending on its chromaticity and glossiness. Lightness of the surface also seems to influence on perceiving metallic colors. In this study we investigated what effects the surface lightness could have on chromaticity region of gold, silver and bronze colors. In the experiments we used CG simulated spheres, presented on a LC display, with various glossiness and chromaticity as stimuli. The lightness of the sphere, which varied with diffuse reflectance of the surface, was set as a variable. The observer performed categorical color naming and estimated degree of gold, silver or bronze color appearance of the stimulus. The results showed that the size of chromaticity regions to yield gold, silver and bronze colors reduced as the lightness increased. There was only a small chromatic region of a metallic color when the surface had low glossiness and high lightness. Similarly the degree of gold, silver or bronze color appearance decreased as the lightness increased. These results indicate that the surface with certain glossiness appears gold, silver or bronze color only below some level of lightness.