
46 Chapter 3
Illuminants with higher color temperatures of
5000K and over appear bluer and cooler, lower
color temperatures of 1700–3200K appear redder
and warmer. The spectrum of white in illumi-
nants transitions from 1700 to 4500K roughly
along the blackbody locus of Planckian radia-
tion (incandescent light), then it is averaged from
about 4500K to 5500K to meet the CIE D series
daylight locus. While color temperature is a sca-
lar measure of near white color, many colors with
different appearances can have matching color
temperatures, and some illuminants with identi-
cal color temperatures vary in how much green
they contain. ...