The planning instead is 2 Research actions (which becomes three) and a Psykana action (which nets two Melodies, when our Choirs have been quite a bright spot.)
It should also be noted that switching from Colonization gets us the ISC special ability that lets us gain its advantages for a turn.
I also would like to repeat my disagreement with
@Amilia that colonizing all of Irridanus will give us a fourth action, because sub-sectors are to one extent entirely arbitrary. What massive increase of our capacity or glorious victory would it actually be to go from two planets in a sub-sector colonized, to all four?
In such a circumstance, I don't think that there is a 4th action lurking behind it, which makes the colonization merely important rather than ALMOST VITAL (which it would be if there really was a fourth action for the turn after locked behind it.)