Colston attended Hofstra University (HU) from 2002 to 2005. He played in 40 games (37 starts) at wide receiver for the Hofstra Pride (HU's football team) and had a total of 182 receptions for 2,834 yards and 22 touchdowns. Colston missed the entire junior 2004 season with a shoulder injury but successfully returned the next year (2005) to be named an All-Atlantic 10 first-team choice.
On April 29, 2006, the New Orleans Saints drafted Colston in the seventh round (252 pick overall) of the 2006 NFL Draft. Surprisingly productive, Colston had an amazing rookie season as he played in 14 total regular season game with the Saints at wide receiver (12 starts) and had 70 receptions for 1038 yards and eight touchdowns. Due to his production, he received the NFL's October Offensive Rookie of the Month award, the first NFL Offensive Rookie of the Month award ever given to a player from Hofstra University.