So far as anyone knows and has proven, zero. There are no aliens known to exist, just a bunch of anecdotes, and no matter how high you stack anecdotes, they never become evidence.
As no aliens have ever been seen it is not known what colour they might be.
Yes in fact is has been seen in many places in America even UFO's witch are the Aliens Transportation. this dude is lying there are no such things you dumb nerd.
The border patrol deals with aliens every day.
No, the other side of the Moon has been extensively photographed and no suggestion of the presence of aliens have been seen.
Not that anyone knows and has proven.
Not that anyone has been able to prove, but it is fun to pretend, isn't it? yes ascropshave been seen
A number of people CLAIM to have seen aliens, or THOUGHT they had seen aliens. So far, though, there has been no proof one way or the other.
Humans have never seen aliens yet.
until now with ANY proof. nowhere and never
It is claimed that they have been seen however if you ask to see one no one can show you one. So my guess is no.
We humans don't know much about these aliens, so this question has not yet been answered positively.
There is no proof that aliens exist. I believe there is no such thing as aliens. Has anyone seen an alien ship? Has anyone seen an alien? No.