# CIE spectral locus

Unmodified dataset and metadata from the International Commission on Illumination (CIE):

CIE 2019, *CIE 1931 chromaticity coordinates of spectrum loci, 2 degree observer*, Vienna, AT. DOI: [10.25039/CIE.DS.mifmy4x4](https://doi.org/10.25039/CIE.DS.mifmy4x4).

- Source: https://cie.co.at/datatable/cie-1931-chromaticity-coordinates-spectrum-loci-2-degree-observer
- CSV: https://files.cie.co.at/Publications-datasets/CIE_cc_1931_2deg.csv
- License: [CC BY-SA 4.0](https://creativecommons.org/licenses/by-sa/4.0/), per the included metadata. This dataset and its plotted locus retain that license, separately from application code. The browser demo plots xy coordinates; the native color lab also transforms them to u′v′. Both close the endpoints with the purple boundary.
- SHA-256: `5a3f0582ea0907867c7a2718051bbdc04f39e758d8c09e628930efc62386e399` (verified against the published metadata).

No network access is required at runtime. Source data spans 360–830 nm in 1 nm increments. CIE classifies these published chromaticities as approximated; plotting does not add measurement precision.