What other colours do Black Holes come in?
We never see black holes themselves: all we see is gas falling in to them. This gas gets so hot that it normally emits either X-rays, ultra-violet light or blue light. Thus most black holes that we could see with the human eye would appear bright blue-white. A few appear yellow, but this isn’t their true colour: the really are blue, but are obscured by interstellar dust.
