Correlated Color Temperature or CCT

Correlated Color Temperature (CCT) is the perceived “color” of the naked eye of the light bulb spectrum emitted by a lamp expressed in Kelvin (K) units

In buildings, it is very important to take the color temperature into consideration of the light fixtures (i.e. Metal Halide Fixtures) used. To promote relaxation, a warmer (i.e., lower color temperature 2700K) light is often used in public areas, while a cooler (higher color temperature 4100K or 5000K) light is used in office buildings. Today there is a heightened awareness that poor lighting can cause stress and sick building syndrome.

There is an international color code to show the temperature (CCT) of a light bulb’s light color. This code is a three digit number (i.e. F32T8/741) The first digit refers to the color rendering index: if it is 7, then the CRI is between 70 and 80, if it is 8, it lies between 80 and 90. The following two numbers are the color temperature (to the nearest hundred) divided by 100 kelvins, and if the temperature is 6500 K (full spectrum), the number is 65.