colour perceived to belong to an area that appears to be emitting light as a primary light source, or that appears to be specularly reflecting such light
Note 1 to entry:
Primary light sources seen in their natural surroundings normally exhibit the appearance of luminous colours in this sense.
Note 2 to entry: This entry was numbered 845-02-22 in IEC 60050-845:1987.
Note 3 to entry: This entry was numbered 17-727 in CIE S 017:2011.