I have a mist bottle I use in my kitchen for various things.  Some over spray got on my red fondant and hours later you can still see every drop.  It made the fondant shiny where the water landed.  How do I fix this? 

I always use clear vanilla to rub off errors on fondant. Just do it very gently. If possible, do the whole thing, so if it takes a bit of the color off, it will fade the whole cake. If not possible, then do it ever so gently with a paper towel.

Then there is always smoke and mirrors. Cover it up with something, if all else fails....