I have only a minor suggestion: when cycling through planets in the colony management screen, it would be nice if the planet order would be sorted the same as the Colony portion of the civilization manager. In other words, if I sort the view in the civilization manager by Building or Starport I would see those planets first when cycling through my planets via the top left/right arrows.

I couldn't find mention of this elsewhere, but thought it might be handy - I know it would be for me.