Siril : 1. Set Histogram 2. Remove backgound 3. Set Autostretch 4. Color calibration 5. remove green 6. Set linear 7. apply autostretch 8. split channels 9. RGB Composting RRG (Luminance R) 10. Remove green 11. Color saturation (Global) 12. color calibration 13. remove green noise 14. Open histogram, use black and mid slider 15. Color saturation => Orange Sii = (Ha*1.024390243902439) R=.4*Ha + .6*S G=.4*Oiii + .3*Ha + .3*S B=Oiii