Don't give up yet. To get the stars under a bit more control you can try using the Morphological Transform tool. It works great after you have stretched your image to tighten up your stars. Just make sure you use a star mask so the only thing you are affecting is the stars.
Also, it could be as simple as needing to get you colors properly aligned. To do that, use the Histogram Transform tool, use a preview and see what your histogram looks like for your RGB image. What you are likely to see is that the colors are misaligned. The way to fix that is to look at the color that is most to the left (most likely the blue if you have green and red halos). click on the other colors, one at a time and adjust the histogram to bring all the colors intop line on the left side.
Other things you can try are the background neutralization and color calibration tools as well as the SCNR tool to remove green tints. Most of these tools have documentation that help explain how they work (you can get the documentation by clicking on the little symbol near the bottom right side of each tool that looks like a little page with a folded edge).
In case it helps, I am attaching the latest version of my workflow and tool tips cribsheet that may give you some ideas too.
Best of luck,
Jim
Good luck,
Jim
