Color is a mode of interpreting information, and sometimes it tells us more than pigment. It can tell us about motion: a black-and-white wheel set spinning reveals the rainbow. It can tell us about depth: Long distances appear blue because higher wavelength red light scatters less. “Color is not an object of sight but a way of seeing things,” writes Mazviita Chirimuuta. Does color even exist? by Malcolm Harris.
Perception belongs not to optics but to the study of the wonderful.Johannes Kepler
Note  but colour reveals the shape of space and time in the universe.