Proco Rat - noob LED help.

[dream_noir]

Okay so I have what I beleive is a Proco Rat 2, it already has the red LED but I would like to change it to blue just for fun and to learn a few things. However, after doing a little research this is just getting more and more complicated. I swapped out the IC for an LM308N already and I really want to do something else. It looks like the pedal has a 3dpt or 3dpdt or whatever switch, from what I've read it looks the same, 9 pins on the switch. I found some diagrams on a page posted here http://www.diystompboxes.com/cnews/FAQ.html for how to wire up the switch, and a. I don't know, is the rat postive or negative grounded. I've read a bunch of stuff that says its the opposite of most pedals, so is that positive grounded then? The way my rat is wired up it doesn't come close to matching either layout b. The led doesn't really seem to be hooked up directly to the switch, instead it seems to be part of the whole circuit. I'm working off a blurry picture I took when swapping the IC's as I don't want to take it apart yet, so I could be wrong on this. c. Does any of this matter for switching out the LED, can I just buy a blue one of the same diamater and swap it straight up? Or do I have to swap a resistor or something also to keep the voltage the same? I have limited (yet quickly growing) knowledge of electric circuits, and well, I know different colours of LED have different voltage drops (I think?), so thats why I'm asking. Hopefully someone has done this before and knows what I'm talking about in some way.

Thanks for any help. 

[Seljer]

You should be able just by a LED of the same size and swap it directly in 90% of cases. You just have to get the polarity right as the original one (if you happen to mess it up it won't do any harm, you just have to turn the LED around).

when looking at a round LED from above it has a slightly flatter side which is the negative side. Also, if you look closely at the inside you've got something that looks like |\ \__| , the bigger side is the negative side.