Another thought about the "black" panzer uniforms... first, black is one of the fasted fading colors there is in cloth. Within a few washings they begin to actually turn brownish-black.
I have a friend (Shawn Southern) who owns an EXTENSIVE collection of WWII uni's, from around the word. These are displayed on mannakins in his den, under good "Natural Color Bulb" lighting. He has two Panzer uniforms from the French (officer with the funky slouch beret) and Polish campaigns (NCO with soft field cap), and both are dark black near the seams, collar, and cuffs, but everywhere else, looks like a charcoal to dark-chocolate color. The trim is a dark salmon color pipping.
With this in mind, i now do my priming in PURE BLACK, then mix medium brown with EBONY BLACK (a slightly brown tint of black) to make my BASE coat. Myhighlights are created using a tan mix with black. In this way, i most closely get what I have actually seen with my own eyes.