Phosphor

In discarded fluorescent lighting, mixtures of rare-earth-based phosphors, the substances that contribute to a light's color, are found in a thin coating inside the bulb.

While currently white light is achieved by phosphor down-conversion, LED color mixing actually has a higher theoretical maximum efficiency, which is needed in order to achieve the 2035 DOE energy efficiency goals.

Like conventional bulbs, they produced white light by converting some of the blue light into red and green with the help of phosphors encased in the bulbs.

The blue light is just adjusted using materials called phosphors.

The other is to use only blue LEDs but coat them with a type of fluorescent substance called phosphor.