Color Temperature

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.

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.