I auditioned a black one at the now defunct MARS Music years ago when MXL was just getting started. The early ones were black, the snazzy green ones came out later. I think they were just V67, and then the "g" designation was added later to indicate a green body.
In the early days of MXL they would asign different model #'s to identical mics, depending on which retailer carried the mic. For example: I was told by Ben Casey, (who was with MXL at the time, but is now with Studio Projects) that the V63m and the V57m are exactly the same mic, in different colors, shipped to different retailers. So each big warehouse dealer, MF, Mars, etc, each had some model #'s unique to them, even though the mics were identical. (although perhaps in a different color) Another example is: the MXL 2003 and the V93 are the same mic. There are numerous others, but that's all that I remember off the top of my head.