Thanks for looking everyone and glad you liked it
Andrew, while the process is a little more convoluted with a few other tweaking steps, I make separate Ha, OIII and SII processed stacks and an RGB stack, I then blend each NB file into the R, G or B in various proportions to try and get some influence from each, usually the ha into the Red, the OIII and SII into the blue and green..obviously most of the signal comes from Ha but that is how it basically is in a true colour image anyway. I also make a combined SIIHaOIII and blend it in as a partial luminance layer and also use the RGB again to improve star colours. I make several blends until I am happy with the appearance...it's lots of fun..I look like
Linguini in Ratatouille while I am going at it
.
Mike