The term you're looking for is "color space".

Depending on what you want to do there's CIE XYZ (maps spectrum of color to a 3 component vector by integrating the spectrum multiplied by three functions), CIE Lab* (describes the color of objects under a specified illuminant), CIE Luv* (to characterize emissive source, nonlinear so the the distance between colors corresponds to perceived differences).

These color spaces are built to objectively describe colors, as seen by a human with typical color vision.