Color Field

a homogeneous colored surface of paper, cardboard, fabric, glass, or some other material, used in color measurements. A color field can be produced by application of a dye to the selected material, by photographic or optical methods, or by excitation of a phosphor. Color atlases consist of rectangular samples of known colors. Visual determination of the color of an object being tested is made by selecting the sample closest in color. In three-color colorimeters the color field consists of two equal, adjacent semicircles; one has the color of the object being tested, the other has the color of the screen on which the primary colors of the instrument are mixed.

In cinematography and color television a color field is used to monitor the fidelity of color reproduction. Here, the color field occupies either the entire frame or part of the frame. The fidelity of color reproduction usually is monitored visually or with a colorimeter. Television color fields may also be used to set and monitor the color purity of the red, green, and blue phosphors of the kinescope and the color of the white field. Color fields (with known color coordinates) are included in universal television test patterns.