will last any longer than white. It's mostly an esthetic choice nowadays. They certainly do look nice on the right boat (your's included) IMHO. When sails were cotton the tanbarking made a big difference in longevity. My grandfather had a huge iron pot that he would use to boil nets and sails for treatment. I've always assumed that white sails became associated with classy yachts since only the rich could afford to have their sails rot prematurely.