We do not actually see colors. What we see as color is the effect of light shining on an object. When white light shines on an object it may be reflected, absorbed, or transmitted. Glass transmits most of the light that comes into contact with it, thus it appears colorless. Snow reflects all of the light and appears white. A black cloth absorbs all light, and so appears black. A red piece of paper reflects red light better than it reflects other colors. Most objects appear colored because their chemical structure absorbs certain wavelengths of light and reflects others.
The sensation of white light is produced through a mixture of all visible colored light. While the entire spectrum is present, the eye deceives us into believing that only white light is present. White light results from the combination of only red, green, and blue. When equal brightnesses of these are combined and projected on a screen, we see white. The screen appears yellow when red and green light alone overlap. The combination of red and blue light produces the bluish red color of magenta. Green and blue produce the greenish blue color called cyan. Almost any color can be made by overlapping light in three colors and adjusting the brightness of each color.
Science EncyclopediaScience & Philosophy: Cluster compound to ConcupiscenceColor - Light And Color, Rainbows, Refraction: The Bending Of Light, Diffraction And Interference, Transparent, Translucent, And Opaque