Building Colonies???HELP!

[dumbluck]

You can build on domed colonies. Let me guess, the build time says "never", doesn't it. If it does, then that means that you have zero population on that planet. You need to transfer some pop. over from one of your other worlds. And next time, remember to put population on you colony ships (with the transfer cargo button, an up arrow and a down arrow on the same button). Or use the "colonize" command whilst the colonizer is over a populated planet. Moving an empty colonizer off the planet before hitting the colonize button results in empty colonizers.

Hope that helps!