ISO 11664-2-2022 "Colorimetry - Part 2: CIE Standard light source" defines three CIE Standard light sources for Color perception testing in Colorimetry: CIE Standard light source A represents tungsten lighting, suitable for Color measurement of incandescent lighting; CIE Standard light source D65 represents about 6500K daylight, for chroma calculation under outdoor daylight conditions; CIE Standard light source D50 represents about 5000K daylight, suitable for simulating chroma measurement under general daylight conditions. This document details the relative Light spectrum Power distribution of these Light sources, covering wavelengths from 300 nm to 830 nm. These Light sources are defined to facilitate Color comparison and conformity assessment under different lighting conditions.