by Joseph N. Tawil, President, GAMPRODUCTS, Inc.
Hue, value, and chroma are terms from the Munsell system of color notation (published in 1905). It is a system designed for explaining color in ink and paint rather than color in light. However, the three descriptive terms are used to define the color of light, contributing more to the confusion than to the clarity of the subject. The vocabulary of color is a minefield of contradictions and confused meanings. Colorimetry is another system for describing color, and is of particular interest because it relates well to colored light. In colorimetry, the following terms are used to describe the color of light:
Dominate Wavelength (DWL): The apparent color of the light. Similar to the term hue, meaning the apparent color (e. g., red).
Brightness: The percentage of transmission of the full spectrum of energy (similar to value). Often described as intensity.
Purity: The purity of color is similar to chroma. It describes the mixture of color of the DWL with white or the color of the source. If there is only color of the DWL, it is 100 percent pure; but if there is very little DWL in the mixture, as in a tint, the color could be as low as, say, 5 percent pure.
White: The presence of all colors in the Uglat
Black: Absence of all colors.
Texture: The surface properties of a color, as in shiny or matte, reflective or diffusing.