A company called Scale Motorsports produces a variety of reproduction upholstery pattern decals that work very well. However, you'll need a second color as they are partly clear to let the other color show through. When painting your interior, use flat color or semi-gloss paints to give a more realistic effect of vinyl or leather. Rub the paint with your finger tip and it will produce a slight sheen, like polished leather. Remember to look at ALL colors available, aircraft, military, armor, marine, any of these may just the right shade that you're trying to achieve.