His son now has a fat gig at the FCC, so Colin knows he's going to get to be a house servant instead of a field hand. Now if he was to say anything derogatory he and his family wouldn't be able to eat at the trough and suck on the government nipple any longer.
He's just doing what he has to do to keep the money coming in. He knows what the score is... no profit in rocking the boat.