CIE Chromaticity Diagram

The CIE chromaticity diagram represents a CIE XYZ color space projection to xyY and its approximated RGB color gamut defined by a working color space. The gamut boundary is based on CIE Standard Colorimetric Observer Data. Two sets of colorimetric data, CIE 1931 2° and 1964 10° observer data, are provided, from 360 to 830 nm, sampled at 5 nm.

Each working color space defines the coordinate values of primary and white point illuminants. These values are used to construct the conversion matrix from xyz to RGB and apply it in order to approximate RGB colors.

The whole gamut represents all the colors that human eyes can perceive. The working color space defines the system gamut, which is usually much smaller.