The Hubble palette was invented to take advantage of human vision being most sensitive in green. This showed faint nebular detail more clearly only because human vision is more acute and sensitive in green.
Here is the same data with the NB assigned to their 'natural' colours.
NII and SII to Red, OIII to Green and OIII to Blue.
Large image 7MB
http://d1355990.i49.quadrahosting.co...CAR_NS_O_O.jpg
My aim is to enhance RGB data with NB data in their 'natural' colours.
Bert