Speaking to the Official Club Website, Colback said: "It's just been disappointing that we are not higher up the table.
"We have got ourselves into a position when we have threatened to really push on but we have not taken those opportunities. It's been one step forward, two steps back sometimes.
"Having been here since August though, I have seen the way the team has improved and the signs are there for Ipswich to push on now.
"I fully expect the Club to be up near the top of the Championship next season and in serious contention for the top six."
The England under 20 international will return to the Stadium of Light at the end of the season, where he is regarded as a bright prospect for the future by Black Cats boss Steve Bruce.