Why are most barns painted red?

Hundreds of years ago, many farmers would seal their barns with linseed oil, which is an orange-colored oil derived from the seeds of the flax plant. To this oil, they would add a variety of things, most often milk and lime, but also ferrous oxide, or rust. ... It turned the mixture red in color.Sep 16, 2008
Why Are Barns Painted Red? - Farmers' Almanac
www.farmersalmanac.com/blog/2008/09/16/why-are-barns-painted-red/