I think it's about time someone comes forward and states the fact that the Hubble telescope has not been emulating the the actual colors of the universe. We can see this most dramatically in the Hubble's images of Mars.
In the article's discussion of the color of the Moon he says the Moon is charcoal color which is the same thing as says gray, different shades of gray. Apollo photos show the Moon to be gray, quite clearly in surface photos with the lander or astronauts in the photos to providing a contrast. When you then that a photo of the Moon from your own backyard with a modest telescope and digital camera you can see a gray Moon. We may not know exactly why the Moon is gray but we do know the Moon is gray.