The amount of energy carried can cause different reactions. Photons with wavelength 651 nm will also appear to us as red, a slightly different shade. Green light has wavelength 500 nm, blue 400 nm. Visible light ranges from 350 nm to 700 nm. Black is the lack of any light.
White light is all the colors mixed together.
When all the colors arrive at once, we see white. White is not a separate color with its own wavelength. Some processes can separate light into its colors. Triangular slab of glass. Light gets bent as it goes from air to glass to air.