What H suggests is basically what I did for my version. I combined with PixelMath in the colour combo I did (much more whacky than his suggestion
). This of course moves you away from the Hubble Palette.
One of the ways you can deal with the Magenta stars is to make a StarMask and then drop the saturation out of the stars. Making a good StarMask can be frustrating at times, but it's worth playing around to see what you can achieve.