Very nice to compare, I like the cleaner fg. The colors look ok to me, but I don’t know what they look like in reality or what you were going for (you mentioned considerably changing them 
). They don’t look unnatural to me at least. If you want the bg hill separated more in tonality, you can burn them with some sort of selection maybe?
That’s an idea - burning down the bg. So far it’s pretty much as was there. The Painted Hills are so outrageous that it’s hard to tell what’s natural.
Very late to this party, but I’ve been traveling, and were at the Painted Hills a few days after you. I recognize this spot. The colors look fine to me - not too saturated. I think you could get away with burning down the background hill and it wouldn’t look unnatural.