Father: Daniel Colson
Significant Romantic Relationships: Sarah "Flash" Roberts, Jennifer Rappaport

Riley is the son of Llanview District Attorney Daniel Colson. He was named after Joe Riley, deceased husband of Viki Davidson; Joe and Daniel had worked together early in Daniel's career. Having suffered a strained relationship with his father, Riley struggled with a drug problem. He managed to get himself sober, using his love of music as a focus. Riley joined the band Midnight Logic, and began to develop feelings for its lead singer, Sarah "Flash" Roberts. Flash seemed unaware of Riley's feelings at first, but eventually she realized how Riley felt and reciprocated. The two fell in love. Flash encouraged Riley to rebuild a relationship with his father, which Riley worked on strengthening.

After a fight with Riley, Flash was attacked by the Music Box Killer. She survived the attack, but suffered throat damage and went to London for extensive therapy. While grateful that Flash was alive, Riley sunk into a depression after Flash moved away. He began to use drugs again, but a developing friendship with Jen Rappaport helped him to realize that using drugs was doing him harm. Jen was a comfort to Riley, and the two grew closer. Riley received a letter from Flash, explaining she had met someone new and wanted to break up with him. Riley was heartbroken, but Jen helped him get through it.

Riley and Jen also bonded on their mutual school problems. Both were failing their classes and had a hard time keeping their grades up. Riley nearly succumbed to cheating when he bought a term paper off the internet. His conscience got the best of him, and he decided to write the paper himself. In an unfortunate mix up, Jen turned in Riley's paper for him, but accidentally turned in the wrong one. Before Riley faced consequences for cheating, Jen explained the situation to his professor, and Riley was in the clear. However, his grades were still in trouble. President Davidson invited Riley, along with other Llanview University students to participate in the rebuilding of the community center. The program required the students to live together for the summer, and build a new community center for school credit.

Jen and Riley were forced to share a room. Soon their friendship became something more, and both admitted they had feelings for each other. Riley felt it would be best to hold off on a relationship for fear of ruining their friendship.

Riley and Jen's relationship hit a bump in the road when Flash sent Riley another letter asking for him back. Jen was convinced that Riley would get back together with Flash, but after some thought Riley realized Jen was the person he loved. Riley told Jen he only wanted to be with her, and they decided to pursue a relationship.

Jen was blackmailed by Paul Cramer with a sex tape of her mother and Jen's ex-husband Rex Balsom. Jen tried various means to get the tape, including almost seducing Paul, and lied to Riley about her efforts. Riley found out and was initially upset by Jen's secretive ways, but the two quickly reconciled. When Paul was murdered, Riley was distressed to learn that Jen topped the suspect list, and that his father was investigating the case. Riley promised to stand by her, with a resolute belief in her innocence. The two decided to move in together, but their relationship has been complicated by Rex's constant presence. Rex has made clear his intention to win back Jen's affections, infuriating Riley.