Suggested optimal "primaries" and concomitant optimal gamut for any form of device or product whose output serves as input to the normal human visual system: TV-like images, or images reflected from illuminated hardcopy. For those devices and products using additive coloration, three spectral primaries 450-530-610 nm, and their associated gamut, are suggested as goals. For those using subtractive coloration, three reflective components, of width perhaps 50-60 nm at half-height and peaking at the same wavelengths, are suggested. Thus, in either case, the light from each pixel of the generated color image entering the pupil of the normal human observer is composed of a mixture of that observer＇s prime colors. "Prime colors" are defined as usual as (a) the wavelengths marking the peaks of the three spectral sensitivities of the (trichromatic) normal human visual system, and, thus, (b) those spectral lights to which the normal human visual system responds most strongly per watt of power content input to the pupil. Spectral sensitivities of the normal human visual system are carefully distinguished from those of the CIE Standard Observers.