White LEDs produce white light in one of two ways: either red, green and blue light (RGB) from individual emitters is mixed together, or a yellow phosphor coating is applied to a single emitter (usually blue). The phosphor approach is usually used for white lighting LEDs as it is simpler to manufacture and drive phosphor-based white LEDs. Phosphor white is also typically more efficient than RGB white and tends to offer much better colour rendering.
Kodenshi supplies several types of phosphor-based white lighting LEDs including COB modules and back light SMD LEDs. LED Engin supplies multi-emitter white LEDs.