The first attempt to scientifically and mathematically quasntify the perception of color.
In 1872, James Maxwell, a Scottish physicist, developed a chart in the form of an equilateral triangle and suggested that all known colors could be located within this triangle. The Maxwell triangle identifies red, green, and blue as the three primary components of light, the primary colors at the corners of the triangle. These are the same colors that are the basis of television and computer color monitors. They are the primary colors of light, rather than of pigment. In the center of the chart is white—the color produced by the combination of all components of the spectrum. All colors can be arranged within the triangle. As one moves along its edges, the transitions are experienced: red changes to orange, then to yellow, and finally to green; green changes to blue; blue changes to violet, to purple, and back to red. Moving from the edge to the center of the triangle, the brilliance of each primary color is lost in a transition from full saturation at the edge to white at the center. Maxwell superimposed grid lines, drawn parallel to each edge of the triangle, in order to establish a system of color notation. Any point within the triangle identifies a specific color sample, and was assumed by Maxwell to be definable by the quantities of the primary color it contains. This quantity can be measured by the distance from each primary color. In Maxwell's triangle any point—any color —is defined by only two dimensions, the distance from point 1 and point 2.
Maxwell's triangle paved the way for the Munsell color space and the CIE color space. See Color: Color Measurement.