The friendliest place on the web for anyone with an interest in aquariums or fish keeping!
If you have answers, please help by responding to the unanswered posts.
I suspect that you could probably get away with painting it using some type of enamel (definitely no latex-based paints though), although I wouldn't recommend it as it is hard to tell what sort of things may end up leaching from the paint and into your water. A little research into what sort of paints are used on aquarium decorations would probably tell you what type of paint to use. A good question
Krylon Fusion, evidently the chemical reaction remains inert. My friends use it to paint the plumbing and false backs of their custom nano-reefs. If corals in a 6 Gallon tank are ok with it... I'm sure it's ok.