When you accidentally buy an ugly color filament, what things do you use it for?

I can’t use it to make prints that I give to people because it’s ugly. I can’t use it to make prints that will be prominently displayed because it’s ugly. As of now, I haven’t started finishing/painting my prints, so rule that out.What kinds of things can you print that are all about functionality, appearance be damned? http://ift.tt/2syGRHL