I'm making my son's birthday cake, he wants choc cake with choc icing but he wants it blue! I'm wondering if anyone has done two layers of icing? Any tips for me? I was thinking if I put it in the fridge after I put the choc icing on, it might be firm enough to "re-ice". One more thing....I cant use fondant because he hates it. LOL

You could do it with two buttercreams like you said and chill well in between. But you could also do a chocolate ganache covering then the blue buttercream.

You could but of course like you said to put in the refrigerator. I would say to make sure that you use the big icing tip for the blue and not to touch the chocolate icing underneath it!

The ganache would be easier but he LOVES my choc icing. I'm tempted to ice it in chocolate and pour blue candy melts over the whole thing!