I've done a few planes in the tricolor scheme using latex. I spray the lighter colors first but usually some of the darker color does get on the lighter ones. I go back over the lighter colors with the airbrush and touch them up where the darker overspray got on.

With latexes, you want lower pressure and higher volume. If you use too much air it makes it dry too fast. You also have to play with the thinning to get it to flow right. Also, I keep a small bottle of water with some Mr. Clean in it, and a small stiff brush, to keep the gun and/or airbrush tip clean.

Jim