The practice of specifying or creating colors using three stimuli. These may be additive (RGB) or subtractive (CMY) primary colorants; three attributes such as Lightness, Chroma, and Hue; or three purely synthetic mathematical constructs, as with CIE XYZ (1931) or CIELAB.
A three-valued signal that can match nearly all colors of visible light in human vision. This is possible because of the three types of photoreceptors in the eye. RGB, YC, and similar signals are tristimulus, and can be interchanged by using mathematical transformations (subject to possible loss of information).
A method for communicating or generating a color using three stimuli – either additive or subtractive colorants (such as RGB or CMY), or three attributes (such as lightness, chroma, and hue).
1) Of, or consisting of, three stimuli; generally used to describe components of additive mixture required to evoke a particular colour sensation. 2) Colourimeter: An instrument that measures tristimulus values and converts them to chromaticity components of colour.
The tristimulus values of a test color are the amounts of the three primary colors in a three-component color model needed to match that test color. The tristimulus values are most often given in the CIE 1931 color space, in which they are denoted X, Y, and Z.
The concept of tristimulus originates in the world of colour, describing the way three primary colours can be mixed together to create a given colour. By analogy, the musical tristimulus measures the mixture of harmonics in a given sound, grouped into three sections. The first tristimulus measures the relative weight of the first harmonic; the second tristimulus measures the relative weight of the 2nd, 3rd, and 4th harmonics taken together; and the third tristimulus measures the relative weight of all the remaining harmonics.