If the colony was in the same star system, traveling there at sublight would take months. If it's in a different but close-by system, you could maybe get there in a couple of years if you could travel at close to lightspeed, but a) getting close to lightspeed without some major physics trickery like a warp drive is ridiculously hard and b) at that speed, you'd run into relativistic effects, making the time go much slower from your perspective than everyone else's.