I have a new airbrush kit and used it to make a cake dark blue. It looked fantastic, but when everyone ate it, our mouths turned blue! Good thing it was just for my family!

Are you supposed to mix the color with water/vodka/vinegar or anything like that? Am I just overapplying? I am using AmeriMist airbrush colors.

(mod edited to add correct brand of colors used.)

I don't think so. I think the only way to get around that is use softer colors. I almost always mix vodka with Americolor, mostly because I want to soften the colors. But if you are shooting for navy, I would just go straight color, usually I'm going for lighter shades. You can also mix white with color, but it will produce a lighter shade, and white also clogs the airbrush, so wash well after.