What does chromaticity mean?
Chromaticity is the technical measure of a colour's quality as determined jointly by its hue and its saturation, deliberately excluding any consideration of brightness or luminance. In other words, two light sources with the same chromaticity differ only in how bright they appear. The concept belongs primarily to colorimetry, the quantitative science of colour measurement, where colours are plotted as points on the CIE chromaticity diagram — the familiar horseshoe-shaped chart introduced in 1931 whose curved boundary traces the pure spectral colours. Engineers use chromaticity coordinates to calibrate displays, define broadcast standards such as white points, and ensure consistent colour reproduction across cameras, monitors, and printers. Because the term is inherently mathematical and domain-specific, it carries no everyday connotations and appears almost exclusively in scientific, engineering, and professional imaging literature. Its value lies in precision: it lets practitioners describe colour objectively, replacing subjective impressions like 'warm' or 'vivid' with exact, reproducible numbers.
nounThe quality of a colour that combines its hue and saturation, considered independently of its brightness or luminance. It is a technical measure used in colorimetry to specify colour objectively.
- In colorimetry and display technology: the measurable quality of a visual stimulus defined by its hue and saturation (its 'chroma'), specified independently of luminance, often as coordinates on a CIE chromaticity diagram.
"The engineer calibrated the monitor by adjusting its chromaticity coordinates to match the reference white point."
"Two lights can have identical chromaticity yet appear different in brightness to the observer."
"Broadcast engineers specify standard illuminants by their CIE chromaticity coordinates rather than by subjective descriptions of colour."
The plural 'chromaticities' is standard in technical literature when comparing several measured colour points, e.g. across displays or illuminants.
"The study compared the chromaticities of the three prototype panels under daylight illumination."
Every screen you own earns its colours on a horseshoe-shaped chart invented in 1931 — the CIE chromaticity diagram — where pure spectral colours trace the curved edge.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of chromaticity
Chromaticity derives from the Greek root chrōma ('colour of the skin'), transmitted into English through 'chromatic', a term borrowed from Greek via Latin and long used of colour and music. As colorimetry matured into a quantitative science in the nineteenth and early twentieth centuries, scientists formed 'chromaticity' by adding the suffix -ity to 'chromatic', yielding a noun naming the measurable degree or quality of chromatic character. Related words sharing the same Greek root include chroma, chromatics, and polychrome.
Related word forms
How chromaticity is actually used
Chromaticity is a strictly technical term, confined to colorimetry, optics, display engineering, photography, and lighting science; it is rarely encountered in everyday conversation. It deliberately excludes luminance (brightness), so it should be cited when discussing only the hue and saturation aspects of colour. In casual contexts, plain terms like 'hue' or 'saturation' are preferred.
Easily confused with chromaticity
Chromaticity describes hue and saturation independent of brightness in general colorimetry, while chrominance is the specific video-engineering signal component carrying colour information in television and image encoding.
Chromatic is an adjective describing anything relating to or producing colour, whereas chromaticity is the technical noun denoting the measured hue-and-saturation property of a colour stimulus.