Many artists and scientists have been concerned, throughout time, with the correspondences between color and sound. Numerous studies on the subject have been written. There are approaches based on intuition as well as approaches based on psychology, psychophysics, physics, and physiology. The classical comparison relies on the fact that the stimuli for the sensations of pitch in sound and hue in color are mainly determined by the wavelength of the auditory energy and the visible energy, both taken as undulatory phenomena. On this basis, a comparison is usually drawn between the chromatic scale of sounds and the hue circle. This criterion has been followed to such extent to relate a sound of specific frequency with a determined spectral color. The comparison can be expanded and refined by considering the other variables of sound and color, too. This article relates luminosity of color with loudness of sound, saturation of color with timbre of sound, and size of color with duration of sound There are psychological and physical arguments to support such a comparison.