[Jeb]

I'm pretty sure colony type is there so that AI ministers will know what to build. Unfortunately, this means that a user-defined colony type will leave ministers even more clueless than they already are, unless you edit the relevant .txt files to include a special build queue.

My favorite new colony type is "Warehouse," which is just a planet with a couple of storage facilities. It's useful for tiny planets that aren't worth mining, etc. and aren't as efficient as large planets for research because you can't build many research centers and then a computer complex to give them all a bonus.