CIE standard chromaticity diagram

[4.6.3.1] One in which the x and y chromaticity coordinates are plotted in rectangular coordinates.*

Note: The diagram may be based on the CIE 1931 Standard Observer or on the CIE 1964 supplementary Standard Observer. (See note to color matching functions [spectral tristimulus values].)

* CIE Technical Report 15.2, Colorimetry, 2nd ed., Vienna, Austria: International Commission on Illumination; 1986.