Astro Pixel Processor - Star Color Calibration not working as intended

Hi,

I bet the „problem“ is that the nebula is shot in narrowband. Especially if you have the SHO palette, you won’t achieve a natural star color. Narrowband is inherently false color. If the star colors are important, many people substitute the stars with natural RGB data.

CS!
Björn

I am yet a beginner, so please excuse my most small minded questions.

No need to apologize! Intelligent people ask because they want answers.
A DSLR is designed by the manufacturer to produce true colors under normal conditions. Any filter modifying the spectrum will alter the color and as you're correctly stating an L-Pro which is rather a narrowband blocker is less extreme then an L-eXtreme  which cuts even more of the spectrum of the stars (emission nebula data is narrowband data). But here ends my wisdom about these filters as I don't use light pollution filters. I'm certain someone will provide you some good advice if and how colors can/could be recovered.
For the LeXtreme, it’s similar to creating an HOO image with a mono camera, where the Halpha goes into the R channel and the OIII data into the G and B. With this, it should be possible to calibrate the star colors to some extend but I haven’t tried to full extend.

Best,
Björn