Admin: if not allowed, please remove.
Disclaimer: This is only my edit. The data used to create my final version came from the Hubble Space Telescope and the folks at M.A.S.T. and Hubble Heritage @
https://archive.stsci.edu/prrepds/heritage/
I want to get into narrowband imaging of the universe sometime in the future but had no idea how to process the different filters into a colour composite. I asked on a forum called Cloudy Nights and someone directed me to the Hubble Heritage site where some data can be downloaded. While this is only a small portion of the effort that goes into creating these images, I find it quite fun and can't wait to have my own setup one day, albeit not a billion dollar telescope floating in space.
Here's what I did: I developed the 4 .fits datasets in FITS Liberator 3 into 12 different files. Each one was processed as a darker, mid-range, and brighter image. I took the sets of these and processed them as a tone mapped HDR in Photomatix. I brought these 4 tone mapped images into Affinity Photo and created a false colour image. The filters types got the following colour assignments: 435W got blue, 555W got green, 814W got Red and 658N got red.
I then brought the darker set of the images into Affinity Photo and created another false colour layer and used the blend range tool of Affinity Photo to further restore some more of the highlights.