The can't touch what you have, but they could encrypt it. That would prevent you from developing an offline editor to make things they don't want you to be able to (still) make.
Of course, I can't imagine any actual bitmaps would be stored anywhere, just lines of "slot X texture N color R G B scale Z".
It doesn't matter to me where they get stored, I'd sacrifice a character slot for the space to store all my costumes if it came down to that.
Showing exact numbers on mouse-over would go a long way towards this, it would be a pain to write it all down by hand, but at least you could re-create yourself exactly.