Woodland Farms, how would you get the paint out? It doesn't come out like show paint does it?
What I would do is build it like normal with white then dust it with a white and black at the same time or white and brown or try brown and black too. A light dusting of one or the other might do the trick too. The is though like was said before is to practice and experiment with different mixes and colors. Sullivan's also carries a smoke touch up that might be worth a try.