One of my coworkers asked me a really good question today: Why can’t you see colors in space with your eyes? I actually did not know the answer so I went in search of it. I experienced this phenomena first hand when I visited the Chabot Space and Science Center in Oakland for the first time. The object they had in focus in their huge telescope was the Dumbell Nebula, which looked like a white fuzzy blob through the eyepiece of the telescope. Does color really exist in space? I found a really good explanation below but you just want the Cliffs Notes, the light in space is too dim to activate the color sensing portions of our eyes but CCD cameras are sensitive to the colors in space and are able to record the colors we can’t detect:
“The brilliant colors you see in astrophotos of nebulae are too faint to be seen live, even through a telescope. Most nebulae are just too faint to trigger the color sensors (cones) in your eye, so you see them with your monochrome night vision (rods). In particular, you can’t see the red color that’s in a lot of photos; not only is it faint, but it’s also in a part of the spectrum your eyes aren’t very sensitive to.
You can certainly see colors in planets – Mars, for example, is distinctively reddish. I’m sure the blue of Earth would be quite striking if you were seeing it from Mars.
If you look carefully, you will see that stars vary in color – some are bluish, while others are yellowish or reddish. The colors are not intense because stars emit a continuous spectrum; you only notice the color when it is skewed to one end of the spectrum. You can also see blue or green in some of the brighter nebulae, particularly planetary nebulae (source).”