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.
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.
