My nephew was all green all the time until last year. Got fed up with the green service restrictions, delays and cost. Got a deal where he ended up with 3 new red machines for the cost of one green one and is now moving to a more colorful fleet. Had an issue with a red combine and they got him back up and running in 2 days.
I was pretty sure we were going green when our Cat combine blew up years ago and the engine replacement was cost prohibitive.John Deere quality and service has gone down over the years.
We looked at the green and were appalled at how small the separator area was, how much shielding was around it and the engine, and how hard it was to work on.
IMO the poor design might be catching up to them and giving the a reputation of having bad service, just because there are certain components constantly needing attention, and the shops are overwhelmed.
Just some speculation on my part.