Assuming that your "a few hours" is 3 hours, we'd have a ship capable of travelling at approx 5,100,000 m/s (assuming distance to Mars at it's closest orbit is 55,000,000,000m).
Using the same ship it would only take us 322hours to reach the edge of our Solar System (reach Pluto anyway). Interesting Note: this ship is over 650times faster than the average speed of the Space Shuttle!
So, no, I probably wouldn't colonise another planet (Mars is pretty boring anyway), I'd want to start/be a part of a wider expedition.
Been a while since I've done anything even vaguely Maths based, so my calcs may be way off.