Painting Helmets

[DaveASA/FED]

I was asked this question last night and wanted to make sure I was right. Is any organization disallowing painted helmets? I have heard several discussions about this, the paint may weaken the helmet etc. I know that they should not paint over the warning label and that they need to ensure they don't sand or paint so thick that they make the NOCSAE symbol unclear. But do any of you know of any league that has actually "banned" or discussed banning painted helmets??