The whole purpose of Parkerizing is to create a surface that will retain oil and prevent rusting. The fact that it is non-reflective and even better from a military standpoint is coincidental.

The trouble is that it holds not only preservative oil, but crud, dirt, oil from hands, etc., and the result is that it usually ends up a rather dirty brown, not the gray or blackish it was originally. Some folks think the greenish color of some U.S. WWII weapons was due to the Parkerizing absorbing cosmolineicon, but Cosmoline is brownish; the green tinge is due to the chemical composition of the Parkerizing solution used.

Jim