The hue and saturation of a light or color stimulus with brightness taken out, expressed as coordinates on a chromaticity diagram. The CIE 1931 x, y system is the most widely quoted; the more perceptually uniform u', v' system is used for color difference and tolerances. LED makers sort products by chromaticity, and specifiers check it to ensure fixtures match each other.
Chromaticity on the two batches is 0.004 apart in u'v', so they'll look different side by side on the same wall.
Also heard as
- chromaticity coordinates
- x,y
- u'v'
- color point
Related terms
Chromaticity diagram
The horseshoe-shaped chart that maps every visible color by its chromaticity coordinates.
MacAdam ellipse
A small oval around a target color on a chromaticity chart, inside which color shifts go unnoticed by most viewers.
Duv
How far a white light's color sits above or below the blackbody line, giving it a green or pink tint.
Binning
Sorting LEDs after manufacture into groups with matching color, brightness and voltage.