CIE standard illuminants
illuminants A and D65 defined by the CIE in terms of relative spectral power distributions
NOTE 1 These illuminants are intended to represent:
A: Planckian radiation at a temperature of about 2 856 K;
D65: The relative spectral power distribution representing a phase of daylight with a correlated colour temperature of approximately 6 500 K (called also "nominal correlated colour temperature of the daylight illuminant").
See also CIE 15 Colorimetry
See also ISO 11664-2:2007(E)/CIE S 014-2/E:2006 Colorimetry - Part 2: CIE Standard llluminants for Colorimetry
NOTE 2 Illuminants B, C and other D illuminants, previously denoted as "standard illuminants", should now be termed "CIE illuminants".