Jeff Colby is the most decent member of the Colby family. In Denver, he works for his manipulative uncle Cecil Colby and gets closer to Fallon Carrington, his crush from his childhood. He has no idea his marriage is nothing more than a business deal between the Carringtons and the Colbys and, therefore, he puts up with his wife's wimps and affairs. Their frequent disagreements tear their marriage asunder, and it seems increasingly, so he starts considering himself just a dupe who's easily taken advantage of.

Knowing that the Colby name is soiled enough through the foggy kindness of his uncle's pathetic schemes, Jeff decides to incline towards "Denver-Carrington" and to leave "ColbyCo. Oil" behind. Furthermore, he's willing to divorce Fallon and to get custody of his unborn son Little Blake mostly as a consequence of Fallon's sexual and emotional maladjustment.

After a very short and hasty affair with troubled Claudia Blaisdel, caused by her need of lost hopes regarding Lindsay, Jeff seeks source of comfort in Kirby Anders