Color appearance is the term given to the chromaticity of a primary radiator, i.e. a light source (in contrast to the object color of a solid that derives from irradiation). Color appearance is a product of the spectral composition spectrum of the radiated light. The chromaticity of a light source is compared with the color of a black body or Planckian radiator and is expressed in terms of the nearest temperature (cf. Color Temperature). Red chromaticity is in the low color temperature range, changing to white and then blue with rising temperature. Color temperature is expressed in degrees Kelvin (K).


In both the DIN and CIE standards, artificial light sources are classified in terms of their color appearance. To the human eye they all appear to be white; the difference can only be detected by direct comparison. Visual performance is not directly affected by differences in color appearance.


DIN - Classification
 

Abbreviation

Color temperature range Tn

Philips T26 and TC lamp codes

warm color appearance

ww

< 3300K

29, 33, 82, 83, 92, 9330, 31, 32,41

intermediate color appearance

nw

3300K ...5000K

84, 9420, 21, 22, 25

cool color appearance

tw

5000K

25, 76, 86, 95, 9610, 11, 12, 72 

CIE - Classification

Abbreviation

Color temperature range Tn

Philips T26 and TC lamp codes

Group 1

warm

< 3300K

29, 33, 82, 83, 92, 9330, 31, 32, 41

Group 2

mittel

3300K ...5000K

84, 9420, 21, 22, 25

Group 3

kalp

5000K

25, 76, 86, 95, 9610, 11, 12, 72