What is Kelvin And CCT (correlated color temperature)


CCT Chart showing the black body light sources of various lighting temperatures and lines of consistent correlated color temperature

                           LED Lighting CCT Chart

Kelvin AKA CCT (correlated color temperature) is the term used to reference the color of the light. Color temperature is a characteristic of visible light that has important applications in lighting, photography, videography, publishing, manufacturing, astrophysics, horticulture, and other fields. The color temperature of a light source is the temperature of an ideal black body radiator that radiates light of comparable hue to that of the light source. In practice, color temperature is only meaningful for light sources that do in fact correspond somewhat closely to the radiation of some black body, i.e. those on a line from reddish/orange via yellow and more or less white to bluish white; it does not make sense to speak of the color temperature of e.g. a green or a purple light. Color temperature is conventionally stated in the unit of absolute temperature, the kelvin, having the unit symbol K.

Color temperatures over 5,000K are called cool colors (blueish white), while lower color temperatures (2,700–3,000 K) are called warm colors (yellowish white through red). This relation, however, is a psychological one in contrast to the physical relation implied by Wien’s displacement law, according to which the spectral peak is shifted towards shorter wavelengths (resulting in a more blueish white) for higher temperatures.

Basic LED Reference Example Kelvin Color Temperature Scale Chart

LED Lighting Kelvin Color Temperature Scale Chart

For A Deeper Understanding Of Light Emitting Diode Color Measurement, visit What Is LED Lighting Color & CCT binning