[Robotgroup] LED's and Resistors?

[john at cozmicfunk.com]

Hey there. I have a basic question for anyone who can help.

I have a 4.5 volt (3x AA) DC powered LED circuit with White LED's (x-mas 
lights string from Walgreens etc.) and I am adding 3 volt Red LED 
flashing circuit to it. I need to step down the voltage reducing the 
input for the flasher to 3 volts ( obviously reducing 1.5 volts from the 
input).

I have a couple different flasher lights and LED compartments (all 3 
volt DC) I am adding down the line for my hallway sections on my models 
sets. I understand there is color coding on the resistors, which ones 
should I get and where do I find them, Rat Shack , Fry's etc.

This should be simple for people like Andre and Vern and Done and Gray etc.
Thanks, John