Good work here. Things I would change
- your stars, as you mention, have little colour. Sometimes star colour drops, but here they're almost white. They're also so small you might as well do starless. However this could just be because they're colourless so the contrast is higher.
- Not sure about the colour... That's a personal thing of course, but it seems a little muddy? (excluding the core)
That said, the core of this image and the detail captured are excellent. Great work on both of those fronts.
edit: ps, getting the stars right is not easy. I'm working on the Cat's Paw and mine are nearly white as well
