Oops, my bad, sorry, I had never noticed the difference between the 2 shades of brightwork. Eric is correct, most of the bright work is aluminum.
However, the big band at the bottom of the windshield is stainless and the wheel well moldings are stainless steel. If you look close, you can observe the difference. The stainless steel wheel moldings do polish up pretty nice by hand with a light metal polish, and you can see the black come off. I wipe mine down occasionally with a rag with just a pencilpoint worth of metal polish, even Brasso will work.