Or something else. Farmstead buildings are typically remarkably eclectic, depending on their function. So the cow barn might be clapboards and much better construction quality than the house, while a corn crib or equipment shed may be only good enough to stay standing for a few years if the wind doesn't blow too hard, No rules I know of.

FWIW, both of our outbuildings are painted barn red with green shingle roofs and white trim, one has cedar shingles, the other is sided with T1-11 for the moment; I may shingle it when I have the time, inclination and money.