optimal colour stimuli, pl
object colour stimuli that correspond to objects whose luminance factors have maximum possible values for each chromaticity when their spectral luminance factors do not exceed unity for any wavelength
Note 1 to entry: Optimal colour stimuli correspond, in general, to objects whose spectral luminance factors have values of either unity or zero, with not more than two transitions between them.
Note 2 to entry: The luminance factors and chromaticity coordinates of optimal colour stimuli define the boundaries of a colour solid corresponding to non-fluorescent objects.
Note 3 to entry: For a given luminance factor, optimal colour stimuli define the maximum purity possible for non-fluorescent objects.
Note 4 to entry: See also "object colour", "colour stimulus".
Note 5 to entry: This entry was numbered 845-03-40 in IEC 60050-845:1987.
Note 6 to entry: This entry was numbered 17-851 in CIE S 017:2011.