I have to disagree with "all the treatments" will discolor leather. Any leather that has been used is discolored to a certain extend depending on how hard it was used. The slings I have treated with Pecards have not changed color in at least 30 years, and see no reason they will start now. Leather is organic, and once tanned gets dry with age. Museum leather just lays there and is never flexed. Any leather like a gun sling has to be pliable or it too will crack and break.