Fundamentals: LED color chart article gives a brief review on color temperature and how it affects white LED light.
Despite the fact that LEDs produce light by a process other than heating, we still use correlated color temperature (CCT) when describing the appearance of the LED as it relates to the appearance of a black body radiator. Color Temperature is a standard method of describing white color for use in a range of situations and with different equipment, but note that the term degrees kelvin is not technically correct.
Color “Temperature” is actually a measure of the relative amounts of red or blue light being emitted. Higher color temperatures have more blue. White and blue LEDs have a color temperature, but LEDs not in the white-blue spectrum do not.
Most white LED lamps fall under three basic categorical descriptions: “warm white,” “pure white,” and “cool white.” When the glow of the white LED light is slightly yellow, it’s typically around 3000° Kelvin (K), referred to as “warm white.” “pure white” LED light measures at around 4500°K. “cool blue” white light displays a reading of 6500°K or more. Standard for White Color LED Lighting Fixtures document outlines a proposed definition of standard for white color LED lighting fixtures defined within C.I.E. 1931 chromaticity diagram (degrees Kelvin only as a reference measurement).
Warm light is best used in living spaces as it tends to be more flattering to clothing and skin tones. Cool light, on the other hand, is preferred for visual tasks, as it produces excellent contrast. Fundamentals: LED color chart has a table on the end of the article that shows easy-to-remember basics for best application practices for different applications. Which Color Temperature Do You Prefer?
For more LED information read also Notes on LEDs article.