Iso lines for this quality are perpendicular to Planckian loci on those diagrams, published by the CIE.
For a given target, MacAdam ellipses define zones of Gaussian standard deviations around which this quality is indistinguishable. The R9 value extends an index named for this quality. The 1976 version of a diagram depicting this quality transformed the more commonly used 1931 version from X-Y-Z coordinates to L-u-v coordinates. Iso lines for this quality are perpendicular to Planckian loci on those diagrams, published by the CIE. A namesake (*) rendering index quantifies how well a light source reproduces this quality, as compared to blackbody emission. The Kelvin temperature of a light source is more commonly known as this quality's temperature. Popular specifications of this quality include HSV, CMYK, and RGB. For 10 points, name this quality that humans see at specific wavelengths of visible light.
For a given target, MacAdam ellipses define zones of Gaussian standard deviations around which this quality is indistinguishable.
color [or: chromaticity, correlated color temperature]