Do you have any idea is there any difference between this (attached photos) Mamiya 645 lenses, with red "N" or "ZOOM" mark (and different aperture scale) and lenses with white "N" or "ZOOM" marks in front ring?
Are they newer?
No clue. "N" 645 lenses, according to most guesses--informed or otherwise--sported improved coatings over the older "C" series lenses. Did you try the Mamiya site?