 When people had their flesh vaporized from their bones, the  remaining skeletons were either red or green. Tim Burton (I) (qv)  explained this had been done because the movie had been scheduled  for a Christmas release. Also, the red and green skeletons were  first seen in Beetlejuice (qv). When Barbara and Adam were in  Junos office you can see them with other ghouls looking at the  screen.