BS is a wing pattern. In the regular wild type, the wings are barred. In a BS the wings lack the barring and have a very dark black looking apprearance to them. There are Seipels, as above, and there are also Brown Shouldered too. The hens of BS varieties are all a base color of white with dark or black colored splotches throughout the body. Here is a picture of a BS male and hen of mine.
