All additive color phenomena ordinarily presented in introductory physics can be demonstrated with this apparatus. A metal cabinet has hinged front door holding a milk-glass screen and houses three incandescent lamps, each with a rheostat control, and aperture through which the rays project onto the screen. Three different colors, each with adjustable intensity, can be partially superimposed on the screen. Seven different removable filter holders with filters are included, providing a wide variety of demonstrations.