[cyb_]

Having dabbled a bit in astrophotography, I would suggest that color is best used to bring out the structure (and beauty) of the object. Trying to faithfully match the human eye would, unfortunately, cause a lot of that data to be harder to see/understand. This is especially true in narrowband.

[malfist]

The Hubble palette was specifically chosen to make contrast better. So you can actually see different parts of the nebula.

Otherwise it's all just slightly different shades of red and IR.

[stavros]

Plus, what's the point? It's not like anything will change if the object looks a bit more green rather than blue, it makes no difference to the wonder of the universe.