Hey,
If you are using wood as the building material (balsa or bass) you can use household wood stain and that will give you the best imitation.
If not, a base coat of dark yellow with a touch of dark brown for a light under coat. Then a top coat of a mix of dark brown, touch of black, touch of buff, touch of thinner. I wouldn't mix it 100%, maybe 80% to give it some varigation (streakiness).
One thing I do with my wood is to add a number of varying shades of washes once I get the top coat on. I do prefer to go the stain route.