Glad to see you're still working on your build, @Steggs101. You asked for some suggestions, so I'll share mine;
Put some Metaphoric Stones in your Refinery and make some Refined Metaphoric Stones - you can also use some of those Refined Stone in your Workbench and turn them into Decorative blocks. Keep the general look, but mix up your material use a little. It can look a bit plain when you use the same stone all the time.
As for those alcoves outside, you could perhaps fill them top to bottom with whatever colour Gleam wall pieces you think'll work.
You could also do something similar inside for a bit of modernistic lighting - you know, the sort you see in hotels;
Anyway, keep at it man. You're doing fine.