Following his stay in the NFL, Colman coached freshman football at his alma mater Ocean City High School. In 2002 he became an assistant coach and teacher for Oakcrest High School before becoming head coach at Absegami High School in 2003. During his tenure at Absegami, Colman compiled an overall record of 40–15, with two appearances in the South Jersey Group IV championship game, winning it in 2006. Colman's Braves also won three straight Cape-Atlantic American Conference championships. He guided Absegami High School to its only football championships.
Colman joined the Amsterdam Admirals for the 2007 season as a member of the NFL Europe coaching program, serving as an assistant linebackers coach during the team's final season. He spent the next two years as the defensive quality coach at Nebraska, his alma mater. In 2010, Colman joined Bob Toledo's staff at Tulane University where he coached the linebackers. After two seasons in that capacity, he was hired as the linebackers coach at Coastal Carolina.
He is currently a special teams assistant for the Houston Texans.