The RGB LED consists of 6 leads as shown in the figure. It contains 2 Blue LEDs, 1 Green and 1 Red LED. There are 2 cathodes one common for Red and Green, one for both the Blue LEDs.
     Blue LEDs have lower brightness compared to Red/Green so there are 2 Blue LEDs in this package.

I_f (typical forward current) : 20mA
Cut In Voltage
Red : 1.6V
Green : 1.8V
Blue : 2.5V