Another hobby that I dabble in is old tractors, so I have seen a few John Deere bikes at tractor shows and auctions. They only had one model of each style, and each style had its own color. I have seen black, white, light blue, green, and yellow. My memory is a bit fuzzy on which model each color was associated with, but I think the green one was a 5 speed, yellow was a kids' banana bike, blue was a 3 speed, black was the better 10 speed, and white was a lower equipped 10 speed. I have also seen a mixte in white. The ladies bikes of the other models were not mixte frames.
John Deere dealerships try to be a one stop shop for the farmer, so he doesn't have to spend time going around to other places to buy his tools, lubricants, lawn mower, snow blower, barbeque grill, coat, gloves, etc. While the prices may seem high to us, if down time is costing you money, paying more to get back in production sooner is worth it.