CIE Yxy Chromaticity Chart
XYZ tristimulus values and the associated Yxy color space form the foundation of present CIE color spaces. CIE defined a color space in 1931 for graphing color in two dimensions independent of lightens. In this diagram, achromatic colors are toward the center of the chart, and the chromaticity increases toward the edges.
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Correlated Color Temperature
Correlated color temperature is used to apply the general idea of color temperature to those colors that are close to, but not exactly, on the blackbody locus. The blackbody locus, the isotemperature lines, and lines that indicate equal values of Duv from the blackbody locus are illustrated in the chart.
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Isotemperature Lines on xy Chart
The absolute temperature of the blackbody is referred to as the color temperature. These colors would lie in the ideal blackbody locus, as indicated in the xy chromaticity chart.
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