How do I keep the natural red color of the lagoon nebula with this H-alpha Filter after stacking?

I’m kind of new to using filters, so if this is an obvious question I apologize. After stacking and processing my lagoon nebula subs, instead of the beautiful, crimson red color I got an a semi muddy orange/yellow nebula. Please help me with this problem. I use DSS and Gimp for processing. Also here’s the image: https://imgur.com/a/sRzqgsn