Narrowband color mapping

Not sure what program you're using to combine the channels, but in PI, you can do whatever you want. Don't like the typical SHO mapping? Change it to HSO or OSH or whatever. You can even use pixel math to alter the blends. Some people, like Bill Blanshan, have created some pretty nice scripts for normalization of narrowband data. Also, there's the "Foraxx" method which can be found here: PixInsight : Dynamic narrowband combinations with PixelMath (thecoldestnights.com)

Programs like Photoshop, Affinity Photo and PI allow you to manipulate the hues/saturations of individual channels, so you can come up with some interesting combinations that way as well.

I think I first saw it from Seti Astro, but he combines an SHO image with a Foraxx palette to create a rather unique colour scheme. A tool in the Toolbox scripts called CombineImages allows you to play around with the mix before committing to it.

@Arun, take a look at the description in this image; I got tired of the usual Blue/Gold hubble palette and I use some combination of the math listed there, with variations on the weights:

https://www.astrobin.com/h2vpln/

Some of the other images I have processed using variants of that math are:

https://www.astrobin.com/3y9228/
https://www.astrobin.com/4fj438/

I have also started transitioning away from using PixInsight for any major part of my non-linear processing workflow and do most of that work in Photoshop (linear portion and initial stretching are all still in PI). I find most of these scripts to be clunky and slow in terms of workflow, and Photoshop gives me much better control, and I can tweak the color palette very iteratively and visually. Photoshop has a learning curve, but it has been worthwhile for me personally.

Ani

@Ani Shastry - thank you for sharing that beautiful image. I had noticed it, as I have your other excellent work, but had not read the description. Yes, this is exactly the kind of flexibility and result I would like to get.

You and @Robert Habolin mentioned Photoshop. Do either of you have any videos or tutorials in PS you would recommend? I also am concluding that PixInsight is quite limiting (or clunky) when it comes to color manipulation.

Thanks to all of you for sharing these useful recommendations.

Arun H:
Thanks to both of you for the recommendations.

I was using fixed combinations using PixelMath but was not satisfied.

The dynamic combinations and the NBColorMapper process both look great.

I have a backlog of data to process and was not motivated to process it and simply generate yet another boring SHO image.

Using Pixel Math, the possible palettes are endless and take a few seconds to try. I, too, am looking for new palettes to try as well. This might be a bit controversial, but I am finding Pixinsight to be more of a platform for other developers' work. Most of the scripts I rely on are made by others(Seti-astro, etc.).

Ani Shastry:
As for Photoshop tutorials, @Craig Stocks has a fantastic set of tutorials on YouTube under his Utah Desert Remote Observatories channel. They are free and excellent:

Thank you, Ani, this is most helpful!

This might be a bit controversial, but I am finding Pixinsight to be more of a platform for other developers' work. Most of the scripts I rely on are made by others(Seti-astro, etc.).

Not controversial at all!  I was reflecting on the same. Everything that PI does - stacking, post processing, color - some other software is more capable and sometimes faster. The main benefit of PI these days seem to be that it has by far the largest user base, so the truly game changing developments (like the Croman tools) are increasingly made just for PI since the developers do not have the time or funds to manage multiple platforms.

PixInsight core libraries (PCL) are written in C++. Just all the higher level tooling is done in JavaScript. The new Fast Batch Preprocessing (FBPP) is significantly faster than its cousin WBPP.

That being said, using the GPU to execute the majority of the pixel processing operations either through something like CUDA or ROCm, or something bespoke layered on top of Vulkan/Metal/D3D Compute APIs, and doing more things in-memory (DRAM) vs writing out to files, should speed up PixInsight by orders of magnitude.

One can dream…

Rob Lyons:
Give SH/OH/O a try. It is perhaps a slightly more "natural" palette than SHO and is a nice change of pace when your images start looking the same every time. 
https://www.astrobin.com/34oslv/

Looks interesting. What weights do you apply?

Well darn- not even a mention. So I will mention since it is on topic I think. 
Did you catch my YouTube video on this subject?

https://youtu.be/td4Z4_fIQOE?si=Je-bsEQNX5n1-_kZ

Additionally you can see the images that result from my technique... most recently the Rosetteand the North American Nebula. 

The below began life as an SOO image and then Ha was added as yellow/orange. I think this shows the structure of nebula is a way not typically rendered. 



-adam