An LED which has 3 colours in a single diffused case - Red, Green and Blue. This LED comes with 4 pins in common cathode configuration. The longest pin is the cathode. This is to be connected to the ground. The other 3 pins are to be connected to a voltage source through a current limiter resistor. One pin for each colour.

With different pin for different colour, you can control each colour independently or mix them together to provide colour combination.

Among common application of this LED is when you want to provide three different status indicator for your project in a single LED.

These LEDs come in diffused lenses which give you lesser brightness than clear LEDs but more uniform light, easy on the eyes. They are great on PCB. They go easily into a breadboard as well. Each pack has 10 LEDs.