How about adding a colony view option(street view?), where players can see individual planets cities in there empire from ground level. The colony views would differ depending on the planets enviroment, the race architecture, as well as the colony specialication(industrial, agricultural, academic and happiness). It could even show little humans, yor or other aliens walking the streets.
This view option could serve to give players visual example of how life could be on the planets, getting players to bond better with there individual colonies.