Awesome work Ray. As others have mentioned, you've extracted the faint galaxy extensions very well. Love the spiral structure and dark lanes along with the HII regions. The stars with a magenta cast are a little distracting but nothing major. I suspect this may have been caused by the blue channel highlight clipping noted in the histogram. However its not that severe so there could be something else at play. Normally magenta is attributed to a lack of green which may be the clue as its the weaker of the three channels. i.e could probably be slightly stretch more to better match the strengths of Red and Blue. Really its a minor point, but I thought I'd offer this feedback in the scenario you are looking to improve on the data set. Thanks for sharing. Hope to see more.
edit: something I find useful is the RGB colour space chart such as this one -
http://www.colorspire.com/rgb-color-wheel/ Work with the opposites .i.e. to get a balance when there is too much magenta, add green, if there is a cyan cast add red. Of course there is only so much addition you can make to an additive colours space that is RGB i.e. all white 255,255,255 can't be coloured which is a primary reason why managing star profiles is important. I hope this provides greater insight into what you can do with RGB channels.