if they have conquers the best idea is to conquer the banned colony unless they r in a friendly alliance. sometimes some banned colonies have alot of crystals and alot of conquers and not many units..

Why don't we get an admin here to clarify?

Well micker is right, it's best to conquer even banned colony. As I've said before, maybe they are only temporary banned. And if they have conquers, we will free them to conquer them (give them a better owner). And if not, well, that means they are new players. And I don't think ppl will hesitate to conquer a banned colony with crystals on it.

Imo I think conquer 3 gold chevrons or higher is better since it proves that they don't multi (well most of).

Just to toss it out there, I conquered 5 banned colonies to check this out on mars 3. They don't give me taxation or count towards my total conquered colonies so I think it's safe to say that that is the answer :3

Yeah they dont give anything, neither tax nor workers. If at all the banned colony has conquers or crystals, then it makes sense to attack it.