Is it a stunt or sound saber? Switch with or without LED?
For stunt (non-illuminated switch): negatives to the negative of the battery pack, positives to the switch. Resistor on Blue. You may have to try several until you get your favourite shade.
For sound (non-illuminated switch): negatives to the LED- of the BuckPuck (if you use one - I recommend it), positives to the LED+ of it. Otherwise you need a resistor for the LED. With a resistor, the negs go to the LED terminal of the board, the pos go to the VIN.
For a switch with LED it's a bit more complicated.
I hope I didn't mix something up. If so, feel free to correct me
I don't want to be responsible for any damage due to misinformation