CIE 1931 Chromaticity Diagram

The chromaticity diagram defined by the International Commission for Lighting in 1931 shows the chromatic coordinates of a light. The colors present on the periphery of the diagram are saturated pure colors (monochromatic), and inside the diagram we have multi-chromatic lights.
The black curve gives the chromatic coordinates of the heated black body at different temperatures.
Perfect white can be found at coordinates x=0.3333 and y=0.33333, corresponding to a black body temperature of 5600K.
Remark: in case of the white LED NICHIA NSPW300 BS given in figure 3, the standard chromatic coordinates are x=0.310 and y=0.320 (in dashed lines on the diagram) corresponding to a cold color temperature of 7000K.