Colt M1911 and Government Model (commercial version - serial number starts with a "C" but could start with a "W") were oven blued. The metal was heated in a coal fueled oven with bone mixed in. The parts were removed at certain intervals and rubbed down with oakum and whiting. When the desired color was obtained, it was done. The degree of sheen was a result of the polishing of the metal itself. Commercial versions were normally blued, however nickel plating was available but I think this was through their custom shop by request. The military versions (M1911 serial numbers start with "No.") during the 1918 period were almost black in color due to rather poor metal preparation. These are called "Black Army" pistols. The finish didn't hold up well on these guns.