AColor Temperature

The perceived color of a light source varies with the viewer and other conditions. Color temperature is an objective measure of the color of a light source, defined with reference to the temperature to which an object would have to be heated to radiate light in the same wavelengths. While light sources with a color temperature in the neighborhood of 5000–5500 K appear white, light sources with a lower color temperature, such as incandescent light bulbs, appear slightly yellow or red. Light sources with a higher color temperature appear tinged with blue.

“Warmer” (redder) colors

“Cooler” (bluer) colors

qI(sodium-vapor lamps): 2700 K

wJ(incandescent)/I(warm-white fluorescent.): 3000 K e I(white fluorescent): 3700 K

r I(cool-white fluorescent): 4200 Kt I(day white fluorescent): 5000 Ky H(direct sunlight): 5200 Ku N(flash): 5400 Ki G(cloudy): 6000 Ko I(daylight fluorescent): 6500 K!0I(high temp. mercury-vapor): 7200 K!1M(shade): 8000 KNote: All figures are approximate.

113