Colin is the cousin of the Bradys and the mysterious doctor that Jennifer Horton met in Africa and fell for.
Although Jennifer heard Colin was in town, they didn't meet until the Mother of the Year party Lexie threw for Hope at the DiMera Mansion.
When Elizabeth overheard a phone conversation in which he stated the only reason he was going to marry her was for her money, she called it off and went back to England.
Not long after that, Colin wanted to get back together with Jennifer but she was dating Brandon Walker as well as being pursued by her ex-husband Jack Deveraux.
Colin began a relationship with Nicole Walker in order to make Jennifer jealous but was unsuccessful.
Later on, Colin started to blackmail several inhabitants of Salem: Sami Brady for switching Lexie's DNA test results for her baby, and Nicole Walker with a tape of them having sex after she was engaged to Victor.
After Larry Welch was "killed" by Bo Brady, Colin started getting mysterious phone calls.
Later Jennifer was spying on a meeting between André and Colin where they discussed how to enhance the DiMera empire.
At the night of Victor's wedding, Colin was ordered by Larry Welch to kill Bo Brady.
They found Colin Murphy was alive but being held captive and tortured by Bart Beiderbecke and André DiMera.