Last night, I had a 3 tiered wedding cake and a groom's cake which was replicated from a fitted hat. For some reason, I thought it was a good idea to use clear vanilla extract to paint over the hat with (it was satin ice black and looked great) just to get some of the cornstarch off that i could not remove otherwise. Now my groom's cap is shiny black :/

I also forgot to put confectioner's sugar in between my wedding cake tiers to prevent the fondant from sticking. Thank goodness this is for a family member

This is completely a shot in the dark but is there any way to fix my shiny ball cap?

If the fondant is not tacky or sticky, try dusting some cornstarch over it with a big, fluffy clean make-up brush. Might be worth a try.
Good luck!

Kat