The International Commission on Illumination (usually abbreviated CIE for its French name) is the body responsible for publishing all of the well-known standard illuminants. Each of these is known by a letter or by a letter-number combination.
Illuminants A, B, and C were introduced in 1931, with the intention of respectively representing average incandescent light, direct sunlight, and average daylight. Illuminants D represent phases of daylight, Illuminant E is the equal-energy illuminant, while Illuminants F represent fluorescent lamps of various composition.
There are instructions on how to experimentally produce light sources ("standard sources") corresponding to the older illuminants. For the relatively newer ones (such as series D), experimenters are left to measure to profiles of their sources and compare them to the published spectra
Color Formats & Streams
There are three color formats, which are, sRGB, XYZ ang Lab. Each format has its own value range. A True Color model can be applied to a perception core as configuration. In this case, the user can select the bitdepth of the stream (either 8bit or 16bit). Depending on the bitdepth, the range of the streamed values is scaled to fit the possible range.