i was looking at ebay for hermit crab shells and i found some really funny ones, some had spongebob square pants on them lol...now i imagine these are for land hermits, but is there anything silly like this for marine hermits?
I wouldn't risk it. Not only may the paint chip off, or leach toxins, but in the long run, the shells get covered with coralline algae and tube worms, so the paint would end up being totally covered within a few months.