I wanted to do this:
(but it wont work, becuase you would get a Defeat message at Startup)
ALL the parts go together to make the design:
A) Make
ALL the planets uncolonizable, with a Star DDS textures (ALL of them!!!)

Make
ALL the resource Asteroids the shape of planets, With Planet DDS textures
C) Get rid of regular colonization, rename the Crew Extractors as Colonization, and put the renamed "crew extractor" abilities on the capital colony ships.
With a few minor modifications, and you get the galaxy to look like a galaxy. The point is to
Scale Up the universe dramatically...
You could do as the Starwars mod does and increase the gravity wells to a million, and make skyboxes that look like the Deep Space Field pictures, with a hundred galaxies of different shapes and sizes...
This would work so well if it weren't for needing planets to keep the game alive: If you made an exception with homeworlds, you would have to keep your homeworld well protected, or lose the game in one attack!!!
Can we get the developers to make a build of trhe game that allows this mod???