Colin is a CO from Blue Moon. He is a new recruit in the second game in the series, joining Olaf and Grit. He is the first Blue Moon CO that didn't defect from Orange Star, unlike Olaf and Grit.
He admires his fellow Blue Moon CO's, Olaf and Grit and dislikes Black Hole that already destroyed his home. When Colin first arrived in Advance Wars 2: Black Hole Rising, he called all of his superiors "Sir". Grit was not particularly fond of the title, but Olaf never made an issue of it. He is an uptight CO who always tries his best to correctly carry out orders and give respect where it is due. In Advance Wars: Dual Strike he often talks with a stutter.