WHY BARNS ARE RED

Until the mid 1850s, farmers almost always made their own paint, as commercial products were not readily available. Typically, they would mix milk or lime with a base of linseed oil. They often then added powdered rust (which also acted as a fungicide for the wood) or blood from slaughtered animals, as either of these ingredients was readily available. The presence of the blood or rust (or both) produced a paint with a dark red hue, which is why barns were painted that color for centuries until it simply became a matter of tradition.