Im making a toaster cake and i just tried to make gray out of black icing and white fondant it turned blue this cake is due in three hours help!!!!!

Oh no. It's too late for an answer now isn't it. I hope it turned out alright.

If you still need to know, start with white fondant and add just a tiny spot of black then work it in. If you want it to look like chrome dust the entire thing in silver dust. Use a very large fluffy brush like a blush brush. HTH

Were you using wilton black coloring? I have found that it doesn't stay black or gray but turns blueor green. I now use americolor superblack ONLY and it has never failed me!