Grizabella
Could it have had to do with the printing colors available when the deck was printed? Maybe that's the answer. It seems that I recall someone saying something to that effect in a post I read that I can't find now. I've also seen old photo prints where the skies were more green than blue from times way gone by, so that's what I suspect the green skies would be caused by. I prefer blue skies myself. A green sky is really eerie and would remind me of a freak killer storm coming or something.