These are the same RGB LEDs that are used for the WS2801 breakout board.
They're great when you need a lot of color from not a lot of board space.

Features:

• Viewing angle: 120 degrees
• Red: (640nm) @ 250mcd
• Green: (525nm) @ 880mcd
• Blue: (470nm) @ 180mcd

Forward Voltage:

• Red: 2.0-2.5V
• Green: 3.1-3.8V
• Blue: 3.1-3.8V

Documents:

• Datasheet