Chroma
Chroma is how colourful a colour is, measured as its distance from a grey of the same lightness.
In the CIELAB colour space, chroma (C*) is calculated from the a* and b* values. A grey has a chroma of zero, and the most vivid lipstick reds and pinks reach well above 60. Together with lightness and hue angle, chroma describes a colour completely.
The encyclopedia uses chroma in two ways. It sets each shade’s saturation label (vivid, muted or soft), and it helps separate colour families: a low-chroma version of a red or pink hue is classed as nude or mauve rather than red or pink. When chroma is very close to zero the hue cannot be measured reliably, so the shade is given a neutral undertone.
On the lips, high chroma reads as bold and saturated, and low chroma reads as dusty, soft or greyed. Chroma is one of the three parts of ΔE, so two shades that differ only in chroma look like brighter and duller versions of the same colour.
Last verified . How we measure.