The Filter module's 'Fringe Killer' mode is an easy and very effective way to remove unsightly blue and purple halos caused by chromatic aberration.
Simply put the offending stars, including their halos in a mask (one can be automatically generated from within the Filter module, by clicking Mask, Auto, Stars or FatStars, Do, Keep). Next click a few times on different parts of the purple or blue halos and they will slowly disappear with each click.
The Filter module allows for the modification of features in the image by their colour by simply clicking on them.
This time set 'Old Mask' to 'Add New To Old' to add the newly generated mask to the mask we already have.
The 'Context Size' parameter controls the upper size of the detail/structures that may provide context for smaller detail.
It is important to understand that the signal as show during this first stage, is merely signal that is up for consideration by the second stage.
The noise signature of the deliberately left-in noise, is precisely shaped to be aesthetically pleasing for precisely this purpose.
You can convert everything you see to a format you find convenient. Give it a try!