One of the contribution of Issac Newton was the idea that white light is light containing all wavelengths of the visible spectrum.
He demonstrated this fact with experiments on the dispersion of light in glass prisms.
He made a study of color in 1666 and developed the useful Newton color circle wich gives insight about complementary colors and additive color mixing.
He realized that some colors (magenta, purple) could not be produced as spectral colors.
In the 1860s. James Clerk Maxwell explored the use of three primary colors and realized that no additive combination of three primary colors can cover the entire gamut of perceivable hues.
He showed that the set of primaries was not unique, but that spectral primaries more widely separated in wavelenght could be used to produce a wide range of perceived hues.
Maxwell's work could be considered to be the basis for modern colorometry.