My hair is BLUE! Is there anything that will take it out or should I dye over it?

I bought some drabber because I had brassy tones in my hair, but I guess I messed up the measurements or something -- it turned my hair, especially the ends, a very obvious greyish blue colour. I have to be at work soon and I cannot show up with blue hair (it's not the kind of place you can get away with something like that!) so is there anything I can run to the store and put on it real quick to get it out or should I just buy some dark blonde or brown hair dye and cover it up?? My hair WAS light blonde (naturally, but the ends are very sun damaged).