Color And Meaning In 19th Century Sails.

19th Century sailing ships like the Gloucester Schooner shown here, often featured sails tinted in reddish/brown hues. The shade was the result of a sealing treatment of either tar or resin applied to protect the heavy cotton duck from the ravages of wind-driven salt water. 

It's usually assumed that the shades are added after the photo as they would be for a brilliant azure sky or sea, but the the treated sails and the rich hues they carried were a visual part of every working harbor before the Turn of The Century.