we all know the UNSC can terraform (right?) well i thought that it could be a researched idea (especially with the new planets) which would be implemented with the colony ship.
this would therefore make the colony ship much more useful than it currently is (not saying it is not useful). i was thinking something like this
ice->water
water->terra
Larva->greenhouse
greenhouse->terra
barren->desert
porrus->desert
desert->terra
glassed->previous
and you can only terraform a planet once to make it fair.