The breed is a light to moderate shedder. Colors, while historically predominantly white with patches of red, black, or brindle, have grown in recent years to include many color patterns including black, red, brown, fawn, and all shades of brindle. Standard types are generally more athletic with longer muzzles and a more square head. Many modern American Bulldogs are a combination of the two types, usually termed 'hybrid.' In general, American Bulldogs weigh between 27 and 54 kg (60 to 120 lb) and are 52 to 70 cm (20 to 28 in) at the withers, but have been known to greatly exceed these dimensions, especially in the 'out of standard,' nonworking stock. The American Bulldog is a large breed of utility dog descended from the now-extinct Old English Bulldog. Black pigmentation on the nose and eye rims is traditionally preferred, with only some pink allowed. Eye color is usually brown, but heterochromia also occurs, although this is also considered a cosmetic fault.