Minibot decorations?

[DonRotolo]

I suppose this is one for Q&A, but has anyone seen any rules permitting or prohibiting the use of decorative items (that don't affect function or performance) on the minibot? We have two situations:

1. We'd like to put out team number and colors on the minibot.

2. (not 100% seriously) we'd like to put a sound generator that makes a loud "ding" sound when we hot the top (like the 'ring the bell' booth at the carnival). (I also just saw another thjread, maybe we'll play the Mario sound when we're climbing the pole...)