NOTE 1 – The three values of a set of colour-matching functions at a given wavelength are called colour-matching coefficients (formerly spectral tristimulus values).

NOTE 2 – The colour-matching functions may be used to calculate the tristimulus values of a colour stimulus from its colour stimulus function φ_λ(λ).

NOTE 3 – In the CIE standard colorimetric systems, the colour-matching functions are represented by the symbols ${\displaystyle \overline{x}\left(\lambda \right),\overline{y}\left(\lambda \right),\overline{z}\left(\lambda \right)}$ and ${\displaystyle {\overline{x}}_{10}\left(\lambda \right),{\overline{y}}_{10}\left(\lambda \right),{\overline{z}}_{10}\left(\lambda \right)}$