Color Temperature 101
by eduardoangel – June 22nd, 2009
by Eduardo Angel
Color temperature is based upon the principle that a black body radiator emits light whose color depends on the temperature of the radiator. The Kelvin, often used in the measure of the color temperature of light sources, is a unit increment of temperature and is one of the seven International Systems of Units.
The seven basic units consist of the metre, kilogram, second, ampere, kelvin, mole, and candela, which are the units for length, mass, time, electrical current, temperature, quantity of substance, and luminous intensity, respectively.
Higher color temperatures (5000 K or more) are “cool” (green–blue) colors, and lower color temperatures (2700–3000 K or less) are “warm” (yellow–red) colors. A color temperature of approximately 5500 K is generally considered to match daylight.
The Kelvin, named after the British physicist and engineer William Thomson, First Baron Kelvin (1824–1907), is not referred to as a “degree” unlike the degree Fahrenheit and degree Celsius.