There is, actually, though only out of universe.
In the first drafts of the script and in the novelization, the
Martians' ray-guns had a variety of lethal, graphic effects. Victims
were bisected, body parts were cut off, huge holes were blown through
them. Other victims were melted, shredded, or turned into flame. To
avoid an "R" rating from the MPAA, the producers toned down the
effects of the Martian rays, and victims were reduced to skeletons.
When people had their flesh vaporized from their bones, the remaining
skeletons were either red or green. Tim Burton 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
(1988). When Barbara and Adam were in Juno's office, you can see them
with other ghouls looking at the screen.
Source: IMDB Mars Attacks! Trivia