Dark and dreary Death Star

Granted, it's not supposed to be a happy place but the one in my toybox is downright depressing. I'm using the Empire's Weapon skydome and the Imperial Station theme for the terrain pieces. Have lots of light panels on the walls too. When I placed the roof over it, everything was thrown into deep shadow - removing the roof is no good as it just makes it look like the place is lit by sunlight.

Any hints or tips for brightening up the place? I've looked at the Toybox Summit 2015 Death StR and the Takeover Death Star section but I'm still a bit stumped.

Thanks!

I would say try another skydome, doesn't need to be death star since its a closed space. The incredibles skydome is nice in lighting things up for example. But Yeah I would just try switching skydomes until you see you have the best lighting for it. The only thing is that the Death star one might still be your best choice to make sure its dark in terms of what you are going for.