RGB Light Emitting Diodes are Like three LED colors (Red, Green and Blue) built into a single glass package. Most RGB LEDs have four connection pins; One pin from each of the three LEDs and a common pin that is either all cathodes or anodes of the LEDs connected together. Thus there is either a common Cathode RGB LED or common Anode RGB LED type. RGB LEDs can be made to display a wide range of colours by varying the amount of current flowing through each of the LEDs. This can be easily achieved using a Microcontroller with Pulse Width Modulation. When all LEDs have the same current flowing through them, the output colour is ‘White’. Consider using RGB LEDs in Colour Message Display Boards, Fancy Colour Shop Signs, Programmable Colour/Hue Room Lighting.