[quote=@Dogematix]
What difference does the size of the colony ship make? I'm thinking of making a private company faction, a food and drink giant like Kraft or Nestle looking to set up a corporate farming colony and sell back to earth for big space bucks.
[/quote]

No real companies, sorry, but you are allowed Ertsaz companies (as in, not-Nestle and not-Kraft but are clearly those companies.) Size of colony ship determines starting city size and population.