PLEASE go see a PROFESSIONAL!!! I have also done the same thing-- my hair turned platnium--- decided to recolor that night and then it turned pink--- yes pink!!!
I went to the hair stylist the next day-- she stripped my hair and colored it brown--- although because of the colors I had put on she could only use an ash brown/blond-- which looked green. I was told she couldn't do anything to help otherwise my hair would break off.
So please seek professional help!!!!!
Good luck!!!
-wendi