 Bradford City youth team coach Jon Pepper brought him to the club in 2002, and having rising through the junior ranks at City, Colbeck had barely featured for the reserves when he made his senior debut in a League Cup defeat to Notts County on 25 August 2004 at Valley Parade.It was his only first-team game during the season.It was another 17 months before his next appearance for City when he was a late substitute on 7 January 2006 in a 1–0 defeat to Chesterfield.