Colby Granger is a fictional character in the CBS crime drama Numb3rs, played by Dylan Bruno. First introduced during the second season, he has become a part of the team led by FBI Special Agent Don Eppes (Rob Morrow) and is usually partnered with David Sinclair. This connection creates some tension when Colby is accused of being a spy for the Chinese which is confirmed in the season three finale episode, "The Janus List", with the news leaving the FBI team under Don's command shaken by the revelation.