This is a cool document I ran across that answers one valuable question. According to this the oriignal production of the Mark-2 talker helmet was OD. I may be behind the learning curve here but wasn't aware this was common knowledge now.

Nice document Dustin, some of the early color photos showing them are in that color. It's been theorized that the helmets with "MKII' in black ink (inside), were repaint/refurbed helmets due to the stamped nomenclature being hard to read from the paint.