When i first got my snake i asked a similar question and was told not to do this at all. Its just as easy to fine colored Tupperware for hides and it won't have any adverse effects.

Snakes can absorb things through their skin and paint could be fatal even if its non toxic. This was hot it was explained to me so i stayed away from paint all together and just picked up different type hides, and in once case i just bought fake leaves and put it over the one clear hide i had and that worked perfectly.