Thats Really Nice John,
your post inspired me to go back and have a look at an almost identical pic that i took of M46 in April last year... There was NGC2438 sitting in the middle. I used a Gstar Ex with my C9.25 LRGB L1500, RGB 600 each.
My colours seem to be very different tending more to red/yellow, must be in the processing or something? I'll post it up later if you want.
All the best