A colony ship is any ship outfitted with a colony module and used for colonizing. Colony ships are required to establish a colony on an unclaimed planet. They can also be used to move citizens between planets you already own.
Colony ships are expended upon the creation of a new colony, which happens as soon as the colony ship reaches a class 1, or better, planet that is currently unclaimed.
Colony ships cannot be used to claim planets that are already claimed by other races, for that you need a Transport carrying troops, and usually some sort of protecting fighter escort to get the transport safely to the planet in question.
Colony ships used to transport citizens to other planets you own can be reused until they create a new colony somewhere (or are killed or decommissioned).
Core ship design Edit