The 20-year-old midfielder, who spent the whole of last season at Portman Road, has signed an emergency loan deal until January.
At the start of the season, Black Cats boss Steve Bruce predicted that both Colback and Martyn Waghorn would play key roles in Sunderland's senior squad.
However, Waghorn joined Leicester City on transferdeadline day, and Colback's Stadium of Light career also appears to be stalling despite Bruce's insistence that he will be returning to the North-East in the new year.
Colback's only senior appearance this season came as a second-half substitute in August's Carling Cup win over Colchester, and his development has been hindered by the progress of both Jordan Henderson and David Meyler.
Meyler is expected to return to first-team action before the end of the year as he completes his recovery from a cruciate ligament injury, while Henderson has already established himself as a key member of the Sunderland squad and is closing in on a maiden appearance for England's senior side.
With Fabio Capello expected to make changes for next month's friendly with France, Henderson has been touted as a possible candidate for promotion from the Under-21s.
He has been linked with Liverpool and Chelsea in recent weeks, but having worked with the youngster since he arrived on Wearside 16 months ago, Bruce is confident he will be able to keep him happy and content at the Stadium of Light.
I think we've given him two new contracts already, but he can have 32 if he wants, said the Sunderland boss. It's quite refreshing in this day and age to find a young kid who wants to train and play, and who thinks properly. From the moment I clapped eyes on him, he jumped out like no other player here.
His performance for England Under-21s was absolutely fantastic and I believe Capello was there. I've read in the national press that he's going to bring one forward in for the France game, and apparently it's him.
He's completely devoted to football and I hope he stays that way. If he does, he's got the world at his feet. I'm very, very confident that because of the way he is, football is all he wants to do.