Interesting idea, though its something a real astronomy geek might actually giggle about a little bit. See, the colors in a Hubble picture that gets published aren't true colors that you'd see were you actually looking at the gas cloud, planet or whatever. Hubble pictures are black and white images that are colorized through different filters to bring out certain levels of detail that might not be immediately obvious in a real color picture. In some cases, the images are totally false color for the simple purpose of identifying various elements in the clouds, so what could well be a very gray looking nebula in space looks red, green, and blue when published, because someone colorized it that way to highlight concentrations of specific gas types. Some of the cloud picture showing all the bands and details of Venus are a real classic example. Those images are so doctored, it would actually be fraudulent to tell someone that's what they'd see from orbit, because if you look at some of the current images coming back from Venus express (which ARE true color), the planet really does look absolutely featureless white from space.

Its a cool idea, don't get me wrong, and I'm not saying its wrong to do it, just be aware that in many cases those images are as much "artwork" as anything you might make for yourselves.