I have painted several reels just recently and I would advise you to maybe take apart an old baitcaster and paint it first instead of doing your first one on a Revo. If you are unfamiliar with the insides of a baitcaster make sure you know how it comes apart, which screws go where, how washers come off and everything. Take pictures or write it down. Then make sure you put all the parts that are not going to be painted in a sandwich bag or something to keep it together.
***Make sure you tape parts that you cannot remove and you do not want paint to touch.***
All I did is rough up the original parts with maybe a 400 or 600 grit sandpaper to give some tooth. Prime your parts. If you use white primer, the top color will be more vibrant. Grey primer will make them less vibrant so keep that in mind. What works good that looks great is: Go to Autozone or auto store and look for the Anodized look spray paint. It requires a silver base and when you spray the anodized topcoat. You will be saying d**n at depth of the color.
Either way have fun with it but practice on an old reel first.