"Correct" colour is very assumptious. Just becaus it is film, doesnt' mean the colours are correct... Every film has a different colour balance, and in many respects are even more variable than digital..
Eddie T had some good comments re. colour in a thread about a year ago.
He reckons he can calibrate for "correct" colour based on some reference stars.
http://www.iceinspace.com.au/forum/s...ad.php?p=27413 Post #31.
I'm sure you have all seem his award winning 2070 pic
http://astroshed.com/ which is colour calibrated...
IMHO there is no such thinkg as "absolutely correct" colour in Astrophotography. Pretty pics are the go here as far as I'm concerened... So as long as we enjoy what we image and get a couple of "wow's" from friends and family I'm happy!
Cheers