Blue ghosts

Lucas and I had this discussion the other morning.

Me: Did you have any dreams last night?
Lucas: No, not really.
Me: I dreamed about purple elephants (not really, I just used it as a conversation starter)
Lucas: I dreamed about blue ghosts (see, it worked)
Me: Ooh, what did they look like?
Lucas: They were brown with one purple foot and one orange foot.
Me: Wow!
Lucas: And they had 5 eyes and 5 butts. And it had black hair.
Me: Oh I thought you said you dreamed about blue ghosts?
Lucas: Well some of them were blue and some weren't.
Me: That explains it.