Most LEDs that produce white light are manufactured using a blue chip and layer of yellow phosphor (green or red phosphor may also be used to change the light produced and improve color rendering).  The combination of chip with composition and thickness of the phosphor layer affects the wavelength of light and color temperature produced.  Lower temperatures (2,700-3,000 K) are called warm colors (yellowish white through red), and higher temperatures (5,000+ K) are called cool colors (bluish white).

White light can also be produced using RGB systems (that combine red, green, and blue wavelength light to make white) or by coating other higher-energy LED chips that by themselves would produce light in the UV spectrum.