Visual memory in secondary visual cortex facilitates full colored dreaming. Therefore it is likely that human dreams are colorful.

I know two people who dream in black and white and yes, I think they are the exception

You can read a little about the research on this on Kelly Bulkeley's website at http://kellybulkeley.org/black-white-dreams/ He cites some research studies that are relevant.

There is also some discussion of this research in the article on Dreams and Dreaming n the Stanford Encyclopedia of Philosophy at https://plato.stanford.edu/entries/dreams-dreaming/

The answer will be termed in terms of probabilities and tendencies.

An article from the International Journal of Dream Research: Article Content analysis on the potential significance of color in d...

Also see Hoss's article on ResearchGate on a content analysis of color in dreams, at Article A content analysis of color in dreams

Thank you very much @Hendrika Vande Kemp