Mitsubishi did not make a lot of models, but those few released to the market are of different colors. So, it is easy to distinguish the blue MH700 model from the bright pink MH350, and the emerald green MH-20 from the yellowish MH-16.
To the best of my knowledge, all Mitsubishi knitting machines are standard-gauge.
Mitsubishi MH-10
Mitsubishi MH-15, manual/basic, with needle selector
Mitsubishi MH-16, manual/basic, with needle selector
Mitsubishi MH-20, manual/basic, with needle selector
Mitsubishi MH-350, manual/basic
Mitsubishi Color 7 MH-700, pushbuttons
Mitsubishi Color 7 MH-700B, pushbuttons