One 1-oz bottle of Tru-Color Paint brand Flat Rail Brown paint.

Tru-Color Paint recommends a starting pressure of 25 psi for most airbrushes.  800 series paints are designed to also be easily brushable.  If thinning of the paint is desired, use of TCP-15 thinner is recommended.  Tru-Color Flat Brushable Paint dries to a flat finish.  Clean-up is easily achieved with acetone.