Color is the splitting of light into different spectra. Light, by nature, is monochromatic. This means that it has one wave length. The prism experiment has proved that light has many colors. About 7 colors have been discovered.
The colors simply denote the different wavelengths of the "monochromatic" light. The colors are the different wavelengths of light when it is split.
The eye, sees color as a reflection. In the electron sense, color is as a result o electrons being "excited" or promoted from a lower orbital to a higher energy orbital.
