Hubby was awesome last year and purchased an airbrush machine for me. Used it to airbrush one cake and it turned out ok, but the colors seemed to be a bit weird. It was a dinosaur cake, so the muddles colors worked well. Except the "pond" was airbrushed with blue, and turned purple.

Did a second cake where I was going for chocolate brown on the bottom and bright green on the top. I mixed my brown from red & green (Americolor) because I did not have the choc. brown color. On paper it looked great, nice deep brown. On the cake, it turned a rusty purplish color, very odd.

The frosting was IMBC, so it is not a pure white to start with. But I also tested some on American buttercream with Crisco and same thing.

What did I do wrong? Why does everything keep turning these odd shades of purple? Do I really need to get a book on the color wheel? Maybe I got a bad batch of Americolor?

I refuse to use the thing right now because I don't want to mess up another cake, loL! Any help would be greatly appreciated.

One major reason is that you really can't (in my experience) airbrush onto SMBC or IMBC as they are high-fat icings and it just beads up (which is why you got a totally different color result that you were expecting). I only airbrush on ABC or fondant.

KoryAK is correct...Trying to airbrush... even color IMBC or SMBC is very difficult because of the butter content (Which is yellow) and the fat..The colors almost never come out the vivid colors you are looking for and if you mix in blue with the yellow tinit of the icing..You are going to get green.Airbrushing is tricky and if you cross the colors even with over spray it tends to go murky brown...You also have to factor in the base colors which are used for these colors and many start with a dark purple base such as black coloring.