Now, I can't swap out an old green LED for a new blue one and still leave it connected to a mobo header, can I? Or, do I just have to add a resistor (value?)? Thanks in advance!
green leds take less voltage than blue leds. so yes it should work fine as a straight swap and without a resistor.
Good, that is what I was hoping. I just tried it on an old FIC board I have, and it worked fine. So, that saves me some trouble!