Here are a couple of photos of valleys, from which a colour pallet might be developed. There are a lot of yellows, greens, oranges and blues in these photos, with the blue colours mainly appearing in the hills.
I'm not precisely sure how to capture the grandeur of these vistas in a 4" hexagonal tile, but I do think that any reprint of Magic Realm must meet or exceed the current standard for boardgame art, which has been set pretty high by modern boardgame publishers.