I just got my dx 3w rgb LEDs today. I have been wiring one up for purple for my daughters new saber and playing with the resistors. I tried to calculate what I would need, but got some weird numbers I need to check.

Battery is 6V aaa
LED red is FV 2.5V and 350ma

So resistor would be. 6-2.5=3.5 And 3.5/.35=10 ohms. And 2.5*0.35=0.88 watts

If that is right and I put them in series, can I just add up the individual ohms and watts to get the total I need?

Appreciate the double check.