It's an interesting piece, I think the right texture will really pull it together, I'm seeing a whites and lighter blues scheme personally.
a couple of things though: I don't really see what purpose the chains serve other than just to have them. They are too short and thin to tether it, they can't hook to anything etc.
Also, I guess the fan's are it's means of propulsion? which would mean it's an atmospheric rather than space craft, but I see no way it could ever land or come to rest anywhere. Also, having them only on one side it's visually interesting, but very unbalanced, the cannon side would drop down and it would have a lot of trouble actually flying.
Mabye add some thrusters or something to compensate.