RGB LED emits three different colours, Red, Green and Blue and that’s why its name is RGB (Red, Green and Blue) LED (Light emitting diode) and it blinks these three colours, so also called blinking LED. LED is a semiconductor light source and has two leads. It releases energy in the form of photons by applying a suitable voltage to its leads. The photons get generated because electrons get to combine with holes within the device and release energy, this effect is electroluminescence. This is a semiconductor device so colour depends on the band gap of semiconductor material.