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. ... Rust was plentiful on farms and because it killed fungi and mosses that might grow on barns, and it was very effective as a sealant. It turned the mixture red in color.

What is the most common barn color?

Today, the color of barns can vary, often depending on how the barns are used, but red remains a popular color.

Why are barns red in New England?

New England settlers didn't have enough money to paint their farms. So they needed a cheap way to protect the barns' wood. They mixed skimmed milk, lime, and red iron oxide to make a red, plastic-like coating. The coating protected the wood and kept barns warmer in the winter.