On Vision and Colors from a prism, however, the production of white can be demonstrated by using a mixture of colored light from each of the three main pairs of complementary colors: red – green, orange – blue, or yellow – violet. White can be produced from two complementary opposite colors when both of the external causes of the colors excite the same retinal place at the same time. Newton claimed that white could be produced by the aggregation of his seven prismatic colors. He erroneously considered color to be in light instead of in the eye. White is the result of the combination
Key light key (especially when used with fill/back lighting of other colors) can add more emotional depth to a scene than full white alone. In mixed indoor/outdoor daytime scenes, sunlight may appear to be a "warm" white, and indoor lighting to be a "neutral" or artificially-toned white. By contrast, moonlight appears to be "cooler" than indoor lighting. In many cases, the key light is a stage light for indoor scenes, or sunlight for outdoors. A lighting instrument may also be used outdoors to supplement sunlight or as the primary light source with sunlight or skylight serving as fill lighting. Actual lamps, lighting