This will sound harsh now, but I think the model lacks a real concept sketch of what you wanted to spray. It looks a bit like you took your airbrush, made a random flare here, a random planet there and filled up the rest with mixed purple lines.
As a hint for the future: Flare should be in front of the planets, not behind them. A few more colours on the planet instead of the black base-coat could give it more definition. The white ring around it could well use a harder edge/contrast. Keep going, lets see what you can come up with for the final model.
I did quite some blending. The idea came from
googling "nebular space"
The weapons are WIP, as you can see easyly, but I've decided to finisch my Tanks first and then the Weapons... which kills my rating on Cmon ;)
but it's ok for a WIP model