Thanks Dan for your response. My camera is Fuji XE3. I shoot in RAF with no compression, yet still having the same issue. I can open images normally in Affinity Photo in full colors. However, when using the astro stacking, the picture is BW only. Actually, there seems to be color noise, but overal picture looks BW. I tried Adobe DNG converter with exactly the same results. I also tried the Iridient X-Transformer, which seems to work and images have colors even in stacking. Unfortunately I have just the demo, which puts some watermarks inside. You can guess what is the only aligned part after stacking
It would be very nice if this is eventually solved. I just started with this hobby and would very much appreciate using a single tool like Affinity Photo. Especially on Mac, this would make life easier.
Regards,
m