Reply #3: Much of the stuff in space radiates on wavelengths not visible to

[rman]

the unaided human eye (infra-red, ultra-violet and radio frequencies), and much of the radiation that is in the human visible spectrum is to faint to be visible to the human eye.

To make it visible, the picture has to be enhanced and/or translated to colors that are visible to the human eye.
So the colors are 'inaccurate' in the same way that night-vision images are 'inaccurate'; if the colors would be accurate, nothing would be visible in those images.