Authoritative source of illuminant reference white data.

This module is the single source of truth for every CIE illuminant the library supports — :A, :B, :C, :D50, :D55, :D65, :D75, :E, :F2, :F7, :F11, plus the LED, ID and DCI series — and for the two CIE standard observer angles (2 and 10). It is consulted by:

• Color.XYZ.adapt/3 — chromatic adaptation between illuminants.

• Color.RGB.WorkingSpace — when computing the RGB→XYZ matrix for a working space, the illuminant's reference white feeds the Lindbloom primary-scaling step.

• Color.Lab, Color.Luv, Color.LCHab, Color.LCHuv, Color.XyY — every CIE-tagged colour space converts to XYZ relative to its illuminant's reference white.

• Color.Spectral — the integration normaliser uses the illuminant SPDs from Color.Spectral.Tables, which are paired with the chromaticities defined here.

Reference whites for the 11 most common illuminants at the 2° observer come directly from Bruce Lindbloom's tables and are reproduced exactly. The remaining illuminants are computed from CIE 1931 / CIE 1964 chromaticities.

All values are returned as plain lists or tuples of float() — the module has no Nx dependency.