Colin first appeared when Jimmy gives him concert tickets that he's purchased for a romantic date with Chloe, after she reluctantly canceled the plans. Colin stated that he would take his boyfriend instead. Later, when the sky grew dark as Zor-El's eclipse begins, Colin and others watched the strange act inside the Daily Planet office, and he believed that the Apocalypse had started.
Colin arrived at the Kent Farm and was greeted and teased by Lois Lane. She gave him the video camera to film the wedding and the preparations beforehand. He went around the farm asking people to give messages to Chloe and Jimmy. He also filmed the ceremony before a murderous creature broke into the barn and began killing people in search of Chloe. Colin tried to film the monster before he spotted him and brutally killed him.
Colin was never actually referred to by name on screen but his name has been confirmed by a script.
Colin was one of the few confirmed LGBT characters, on Smallville. Tina Greer was implied to be either lesbian or bisexual, in Visage. Truth, featured a scene, where Chloe's temporary ability made a Smallville High student, named Doug, admit that he had a crush on one of his teammates. While she's openly lesbian in the comics, Maggie Sawyer's sexuality was never adressed on-screen.