Processing the Bubble Nebula

[SeattleStarGazer]

I have Ha and O3 masters of the Bubble Nebula NGC7635. I've seen some beautiful images that convey the blue of the Bubble itself in the rich red Ha region around it, but I can't seem to bring out the blue - just varying shades of red. Tried various combinations in PixelMath and get different hues, but all reddish.  Looking for processing suggestions on this one.

[pfile]

https://pixinsight.com/forum/index.php?topic=7751.0

if you follow RickSs flow, you should get the gold/blue colors you are looking for if you start with an SHO mapping.

Ha/OIII probably will not get you those colors but maybe there is a chance if you map it as HHO.

rob