Here Are Two Ways To Get White Light:
1) RGB is the three primary colors mixed white light, or monochrome color mixing and white;
2) through the blue LED issued by the excitation of special phosphor coating to generate white light;
The so-called blue LED excitation phosphor to generate white light technology, simply say that the blue chip issued about 450-455nm wavelength of the phosphor coating into a visible spectrum, replaced by visible white light. Blue LED special performance for the thickness of the coating requirements and design techniques, coating thickness increase or decrease, the visible spectrum has a great impact on the thickness of the visible spectrum will tend to yellow.
First test the white light quality of light, there is a very simple way, only need a piece of white paper, affixed to the top of the LED lamp beads, see wide angle along the edge of the yellow light phenomenon.