Are aliens red or green

Answer 1

If this question means "Why are space aliens typically pictured as green?" there are probably three reasons. These reasons are guesswork, but they are somewhat educated guesses.

1. No one has ever seen creatures from outer space. At this point in earth's history they are imaginary. Green is a really, really alien color for skin. So in early space fantasies and Science Fiction stories, one way to make them appear extremely different from us was to imagine them as having a completely nonhuman color. Also the association with creatures that are green--reptiles and amphibians--adds to the alienness.
2. If you stick to nonhuman colors for skin, you can stay completely away from any racial associations or symbolism, in much the same way that Sesame Street has a lot of blue guys and other toy colors for people.
3. Once "little green men" became a cliche for Martians, the cliche kept repeating itself. In Cartoons, all you have to do is show little green guys with some kind of weird things around their heads or faces, and the audience knows you mean space aliens. It's an easy kind of shorthand for humorous purposes.
   

Of course, "alien" can just mean a foreigner and not necessarily an extraterrestrial. Foreigners are not green.

Answer 2

No.

Yes.

Maybe.

The point is that we do not know their colour.

If they are amphibian, the chances are that they might be green like some of our amphibians.

Since we actually have no source of reliable information we can not tell the colour of aliens, nor can we tell which colour they are not.

Answer 3

People generally think aliens are green because of old sci-fi movies that used this colour and has Carrie don as a trend ever since. Also green usually represents cold, sick and other negative things which many believe aliens to be. But today aliens are depicted as a variety of colours and shapes and no longer are considered evil nessecarily.

Answer 4

As no extraterrestrial alien have been discovered it is not possible to answer.

Answer 5

Because humans are unimaginative.