Color in my dreams seems based on the dream. Once I dreamed I was in the original Lost In Space and it was in black and white. I've had similar dreams if the dream was like a black and white show or movie.
"Wash your ears, or you'll grow potatoes!"
I don't know the degree I really believed it, but that concept of "ear potato" used to freak me out. So much so, in fact, that I've riffed on the idea for a few D&D games.
Hmmm...I've never imagined people could have black and white dreams. That's fascinating. I'd love to know if that phenomenon can occur in people who have never been exposed to black and white media.