I'm honestly not sure if I want to or not yet. I very well may. I think I'm going to possibly turn my old 10 gallon into a sump and will do it then. Until then I don't really mind the hard plumbed look.
I believe Krylon paint works just fine and is safe for fish. Otherwise any spray paint should work and they I believe you just spray a clear coat over the paint but I'm not positive on that. Your best bet would be with Krylon. I plan on doing that when/if I change the stocking in my tank which might be soon.. Depends on when I get the money and when the LFS reopens.