Color Science / spectral teaching excerpt — 2 October 2026

PROVENANCE AND CHANGES
81 rows, wavelengths 380 through 780 nm inclusive, sampled at 5 nm.
Columns: wavelength_nm, CIE1931 xbar, ybar, zbar, relative D65, relative A,
TCS09 reflectance. See CSV header for the exact column names.
Numerical values were transcribed from these publicly readable Colour tables:
https://raw.githubusercontent.com/colour-science/colour/develop/colour/colorimetry/datasets/cmfs.py
https://raw.githubusercontent.com/colour-science/colour/develop/colour/colorimetry/datasets/illuminants/sds.py
https://raw.githubusercontent.com/colour-science/colour/develop/colour/quality/datasets/tcs.py

The excerpt preserves table values, but restricts the wavelength range and
samples the 1 nm observer table every 5 nm. It is NOT a byte-identical copy
of any complete CIE CSV. Official CIE file checksums have not been verified
against this transcription. The teaching calculation uses 5 nm rectangular
quadrature and relative perfect-diffuser Y=1 normalization, explicitly not
a complete standard CRI/TLCI/SSI implementation.

CIE definitions and corresponding official dataset citations:
CIE (2019), CIE 1931 colour-matching functions, 2 degree observer,
DOI 10.25039/CIE.DS.xvudnb9b.
CIE (2019), CIE standard illuminant D65, DOI 10.25039/CIE.DS.hjfjmt59.
CIE (2019), CIE standard illuminant A, DOI 10.25039/CIE.DS.8jsxjrsn.
CIE, Spectral radiance factors of 14 test samples for the CIE colour
rendering index calculation, DOI 10.25039/CIE.DS.wuiuu9cz.
CIE metadata identifies CC BY-SA 4.0. This attributed numerical compilation
is distributed under CC BY-SA 4.0:
https://creativecommons.org/licenses/by-sa/4.0/
Attribution must retain sources and this change notice. Share adaptations
under the same licence. No endorsement by CIE or Colour is implied.

The two metameric reflectances are generated independently by our teaching
algorithm. They are NOT measured materials, CIE test samples or camera data.
TCS09 and those invented reflectances must not be relabelled as each other.

COLOUR CODE/DATA NOTICE (retained for the source transcription)
Copyright 2013 Colour Developers
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