There isn't any sunlight like your thinking lighting it up. Chances are that nebula is huge, prolly at least the size of our solar system or even WAY WAY bigger like light years across bigger. Next as stated its false coloring. I would say its prolly an infra-red. the brighter points on the edge are where the expanding gas is bunched together and expanding out and "hotter" than the area in the center where its cooled and a more blue color. Also take that word "hot" with a grain of salt. Its not likely to be hot at all, Just warmer than the cold space around it.

After that I would guess maybe a chemical spectrograph and false color in some elements or other electromagnetic wave lengths for some flare.