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A great first NB image!
Welcome to both the Narrowband club and the hugely popular Colourblind Astrophotographer's Brigade.
A quick statistical analysis shows that you could clip your dark point on all three channels by about 9000 counts without losing any data, thus making the image much more contrasty, and that the colour balance is, if you belong to the widely accepted "colour agnostic" school where the task is to show relative colours rather than absolute colours, also statistically faultless.
I'm colourblind to the extent of having no red receptors at all (1 in 1000 males, as opposed to the usual milder anomalous trichromat form (1 in 12), so I've thought about this a lot and written my own image processing software (GoodLook 64) to make it easy and painless. Sod's Law states that I'm just about to release the next version in about a week, so if you can hold off till then, I'll post a link. It's fully functional (subpixel level registration, powerful rejection of satellite trails, hot pixels, bad columns, etc, mosaics, deconvolution, wavelet noise reduction and sharpening, arcsinh stretch, zero, contrast, colour balance, masks, starless processing, the lot, and supports FITS and TIFF). Also free to a good home.
Some general techniques on image processing for the Brigade:
(1) Have a button where I can instantly switch the red and green channels (or red and blue channels). Flicking back and forward gives me some idea of what others can see in the red channel, using my green (or blue receptors).
(2) Close, microscopic analysis of the foothill of the histogram in each channel to set the zero point without any colour cast or data loss.
(3) Tools to make the image as a whole, or a region of interest, colour neutral.
The really tricky bit with narrowband is when you start doing Ha/OIII/SII images, and trying to balance them. You get spectacular magenta rings round stars, which can be very distracting to people with colour vision. I've developed good tools for handling those. Basically, divide image into stars and starless, process the starless image, then put the H-alpha only stars back into the image as white.
Send me a PM if I can help.
Best,
Mike
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