RGB LEDs consist of three LEDs (Red, Green, and Blue). They’re all self-contained within the same plastic casing and share either a common anode, or a common cathode.

Due to the differences in electrical characteristics, a larger resistor is needed in series with the red than that of the green and blue.

Approximate values of: 150Ω, 100Ω, 100Ω are suitable with a 5 volt supply.