The fake colors of Hubble photography JAN 25 2010
Those wildly colorful Hubble telescope photos...how do they get them to look like that?
The colors in Hubble images, which are assigned for various reasons, aren't always what we'd see if we were able to visit the imaged objects in a spacecraft. We often use color as a tool, whether it is to enhance an object's detail or to visualize what ordinarily could never be seen by the human eye.
See also this informative Reddit thread.