Congratulations and welcome, Brian. Check out the "Buffman" book here
http://www.caswellplating.com/buffs/buffman.htm
for a few buffing pointers. I think the green is mostly used for, but not limited to stainless steel. I haven't really used the red yet, but I think it's mostly used for the final polishing step on aluminum. But can be used as the final step on other metals too. Good luck!
Steve