Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, and other fields. The color temperature of a light sources is determined by comparing its chromaticity with that of an ideal black-body radiator. The temperature, usually measured in kelvins(K) at which the heated black-body radiator matches the color of the light source is that source’s color temperature, for a black body source, it is directly related to Planck’s law and Wien’s displacement law.

Counterintuitively, higher color temperatures (5000K or more) are “cold”(green-blue) colors, and lower color temperatures(2700-3500K) “warm”(yellow-red) colors.

Categorizing different lighting
Temperature
Source
1700K
Match flame
1850K
Candle flame
2700–3300K
Incandescent light bulb
3350K
Studio “CP” light
3400K
Studio lamps, photofloods, etc.
4100K
Moonlight, xenon arc lamp
5000K
Horizon daylight
5500–6000K
Typical daylight, electronic flash
6500K
Daylight, overcast
9300K
CRT screen
Note:
These temperatures are merely approximations; considerable variation may be present.

 

Color Temperature diagram