Just to illustrate using multiple colors -- here's a vibe pedal I did with four coats of powder. First I applied the black chrome on the bottom half, cooled it, taped it off with high-temp masking tape and then shot dormant burgundy base coat on top. I let the dormant burgundy heat up slightly then pulled it from the oven to cool. I removed the tape and cured the dormant burgundy base coat. After that cooled I masked off the beltline stripe, shot that with bright red, cured that and then cooled. Final coat was clear over the entire box -- it activated the dormant burgundy and did a nice job of smoothing everything out. You can't even feel the stripe with your fingernail.
Lots of good info and technique tips here --
http://www.powder365.com/forum/ -- a lot of those guys are hardcore pros but there's a lot of good information to be gleaned over there. Check out the CUSTOMER PICTURES section to see some of the gorgeous work these guys can do.