Kent State University has imported a variation of squirrels from London, Ont, Canada. It's black coat makes it a stand-out on the campus. The black squirrels have invaded the whole city. I have had red, gray and black squirrels in my buckeye tree at the same time. I had gray and black squirrels in my yard yesterday. I was able to get pictures of the black squirrel.
Here is a link to a sight about the black Squirrels: