When we “see” colors, we are seeing only part of the spectrum of colors that make up white light. The rest of the spectrum is missing. Selecting the color seen can be done in three ways. You can view the object through a transparent material that transmits only some part of the spectrum while absorbing the rest. The object may be colored itself. That is, it reflects part of the spectrum while absorbing the rest. Finally, the spectrum can be physically separated, as it is by interference or by refraction by a prism or rainbow. For example, theatrical “gels” on spotlights produce colored effects for a stage show. Snow reflects all of the spectrum so it appears white, but green paper reflects only the green part of the spectrum. A black cloth absorbs all light, and so it appears black.