Lego Brick Cake icing

See the last post about the cake itself.

But the icing was SO blue that when anyone eats it, including me, the lips, tongue, and teeth all turn blue. And I gave some to the youngest, who is still learning to use the potty and needs some help with wiping and his poop is BLIGHT BLUE. That is so not natural! If ever there was a good reason to have different color icing, that is it!