Welcome aboard Cope...
What paint are you using? Powder paint covers well so by doing the light color first you can go right into the second color and you're done. If you are dipping a liquid paint you have to allow the first color, preferably the lightest color, to dry well before the second color gets dipped on. Airbrushing opens up a whole new world of painting options and by far the most detailed work comes with the air brush, but there is a big learning curve that comes with it, half of which is care and cleaning of the equipment.
Let us know what type of paint you are working with if you will.