If a M1909 were blued, it would not be right. As Jimmy C indicated, all metal should be in the white. Sometimes the highly-polished blades can become stained and take on a grey-black coloration. They haven't gotten around to faking the Argentines - at least not yet.
The part you refer to is the crosspiece, the lower portion of which is sometimes referred to as the quillion (the upper portion being the muzzle-ring). The tang is the portion of the blade that is surrounded by the grips.