I would have made the spiral arms more blue and less green. The shade of green you have used is correct for many planetary nebulae, but not spiral arms. Try and sparkly blue-white with the core a sunshine yellow. But, I love the details and the stars with spikes are great.
Looking good; Steve Coe
-------------------- 150mm 6" f/8 Celestron Refractor on Sirius Mount
80mmED 3" f/7.5 Orion Refractor
Author "Deep Sky Observing" Springer-Verlag
Author "Nebulae and How to Observe Them" Springer
New Canon Xt astrocamera with Hutech modification