Ughhh My client wants a Batman cake and also wants the inside of the cake to be tie-dyed in white, yellow and black. First of all, I'm not even going there with the black. That's just way to much artificial color going into a kids cake. I told her I might could get a gray worked out.  But the more I think about it the more I convince myself it's going to be UGLY! Gray cake??!?  Just looking for opinions! Has anyone ever gone with gray for the inside of a cake? I can't imagine it but thought I would ask and see.

Thank you for any suggestions!!

I did an over the hill gravestone cake before and made the batter gray. Not something I'd do for a "pretty" cake bu it wasn't as bad as i thought it would be and it fit with the theme. You could marble the cake with chocolate cake too that has been tinted black if she was persistent about having black. Just a thought. 

AThanks so much for the help! Guess I will go with the gray. I did try for the chocolate & white marbled idea but she hates chocolate & was not having it! Never mind that it's 3-tiered and plenty of cake to give guests a variety! All vanilla..it's killing me! Lol

There is a site that shows how to do a zebra cake inside, it would be similar to what you are trying to do.

of course she doesn't want chocolate, that would be WAY too ideal to just add a little black to an already dark batter.

Although, I actually don't mind the idea of gray cake, personally.