Linked from
The 54 pages that link to Colorimetry, each with the reason it gives.
Visible spectrumRelated: Colorimetry maps visible spectra to reproducible color measurements.
LuminanceRelated: Luminance is one dimension used in color measurement, distinct from chromaticity.
AbsorbanceRelated: Colorimetric assays infer analyte concentration from measured absorbance.
Diffuse reflectionRelated: Diffuse surface reflection underlies many object-color measurements.
Sky blueRelated: It provides ways to define and compare particular sky-blue samples.