CCT stands for color corrected temperature and refers to the appearance of white light, specifically how ‘warm’ or ‘cool’ it looks. Color temperature is stated in degrees Kelvin (K) takes its measurement from heating a black body radiator (such as a piece of tungsten) until it is white hot, and the hue of light emitted from it is matched to the color from the lamp.
Lamps considered warm in appearance will be from 2700K to 3000K and are best suited to domestic and hospitality environments. Cool coloured lamps from 3500K upwards are better suited to office and retail type environments.
Increasing with the advent of LED technology, the quality and the stability of the LED’s CCT is becoming a major consideration. Firstly because high lighting levels from LED are nearly always at the expense of color quality, resulting in the LED being an unpleasant blue or green.
Secondly, considering the way LEDs are made and the high temperatures they operate at great care needs to taken when choosing an LED solution and the luminaire it goes into to ensure they offer good color stability over life.