We'll be quite lucky if we can build a colony on the moon, and that's a far closer goal. We know people don't do well in zero gravity, it remains to be seen how well we hold up in 1/6 gravity. It might be enough to keep the worst of the effects from happening.

Anything we do on the moon is going to have to be sub-surface to get away from the radiation and dust problems.

I don't see us getting a colony on Mars without non-chemical propulsion.