I'm trying to power a RGB-LED from an Arduino Pro Mini (3v3, 8MHz variant) and have got confused over how to connect them up. The reason for my confusion is that 2 of the 3 "colors" have got an forward voltage of 3.2V while the 3rd's is at 2.0V. What confuses me furthermore is that the LED is a common anode-type of RGB-LED so I don't know where and what value of a resistor I should put in series with it. Should I use 2 separate resistors - one for the two colors with the If = 3.2V and one for the single color with the If = 2.0V? But then again the 2 similar colors will draw a total of 0.020+0.020 milliamps through their shared resistor when both are lighted at the same time, right?
Note that I'm going to GND them to 3 digital pins on the Arduino so I can regulate their individual intensity with PWM and power them from the Arduino's Vcc pin (because that's possible, right?).
Thanks in advance!