Color vision is known best by man´s perception of it. It creates a unique dimension to sight that is impossible to appreciate by any non-visual means. It depends on wavelength more than on the energy of light but it is an illusion of reality resulting from a comparison of the responses of nerve cells in our brain. Color and all vision are in a sense illusory depending only on messages that pass between millions of neurons that reside within the darkness of our skull. These visual messages allow us to project ourselves into a universe that would be unknown to us without vision.
webvision.med.utah.edu/color.html#start