Here is the finished colored Space Girl art for my Phoenix Comic Con Badge Contest entry.
To be clear, as I've had a few people ask: the background is drawn in pencil (to be more specific, I blacked out the entire background that was to be space, then erased in the details of the nebula and the smoke stream from the jetpack. I then created a mask from a photocopy to protect the girl and planet and spattered on the stars). I then colored it on two separate transparency layers in Photoshop to keep the stars white.
The planet was colored in much the same fashion, painting over the pencils to lighten them above the colored tones below.