Correlated Colour Temperature (CCT) in lighting refers to the mechanism that allows the colours of light emitting from a lamp which is measured in Kelvin (K).
Colour temperature does not match with the actual temperature of the lamp itself rather it's quite the opposite. The lamp with a 'cooler' outlook will have much higher colour temperature.
Temperature of the colour changes with increasing temperature - from red to yellow then blue. The varied range of colours at different temperature is correlated to the scale and quite useful to describe the colour tint of the white LED lights.
When the iron is heated enough, and the temperature reaches around 2700K, it starts glowing like a typical incandescent lamp which is generally referred as 'warm white'. More heat is applied upon the iron will continually change its colour; it will turn from red, yellow to bluish white finally it glow like daylight.
"Incandescent light bulbs lit the 20th century; the 21st century will be lit by LED lamps."
One link that had been missing for over 30 years was discovered the three scientists when they developed the first blue LED light in the year 1993.
Colourful LEDs have been in market since 1960s, but without the colour blue, there could be no clearer, brighter white lights. Invention of elusive blue LEDs transformed the world of lighting technology forever, creating the brightest and the most efficient white LEDs.
As far the application of the colour varied LEDs are concerned, there's no particular rule rather it's more about your personal preference and use. Warm white light with 2700-3000K is supposed to be an ideal domestic choice. Whoever wants a clean and modern look may choose brighter cool white lamps with 4000-5000K.
Selecting the perfect colour temperature for commercial applications depend mostly upon the kind of mood you want to create to promote your product; for e.g. bakery products will look better under warm white lights, whereas apparel and jewellery products clean white lights to bring out the best in it. Lighting intensity required for the industrial sector i.e. high bay light setting.
