Jeff used to work in I.T, and developed a music software that was supposed to belong to Carrington Atlantic, but a judge disagreed and Jeff went on to earn his first billion dollars, which made him Blake Carrington's number one enemy, who admits to hating him on multiple occasions.
In "I Hardly Recognized You", after Blake refuses to give Fallon Carrington a job of importance in his company, she teams up with Jeff, and he offers her financial backing to be chief executive officer of Carrington Windbriar, her own company that she's starting, which will also be Blake's new competition.
In "I Answer to No Man," when Fallon gets kidnapped by Alejandro. Knowing that Michael was sent by Blake to watch Jeff, they both start to fight and after they fight the two work together. It could be the fact that Michael asks Jeff for help to save Fallon.
He has a father who was arrested on alleged drug charges and sent to prison after Jeff's mother was having an affair with Blake Carrington, and Blake wanted Jeff's father out of the picture. When Jeff found out about it, he started a plan to get close to the Carrington's in order to get revenge.
In Trashy Little Tramp and Dead Scratch, it is revealed that Jeff and Monica Colby are half-cousins to Fallon Carrington as as Thomas Carrington, Fallon's grandfather, had an affair with the Colby's grandmother.
Their relationship was business like before it turned romantic however fans doubt Jeff's intentions with Fallon after he confessed to his father in the midseason finale that he is using Fallon to get revenge.
Season 1: (20/22)
|Dynasty: Season 1 (20/22)|
|"I Hardly Recognized You":||"Spit It Out":||"Guilt is for Insecure People":||"Private as a Circus":||"Company Slut":||"I Exist Only For Me":||"A Taste of Your Own Medicine":||"The Best Things In Life":||"Rotten Things":||"A Well-Dressed Tarantula":||"I Answer to No Man":|
|"Promises You Can't Keep":||"Nothing But Trouble":||"The Gospel According to Blake Carrington":||"Our Turn Now":||"Poor Little Rich Girl":||"Enter Alexis":||"Don't Con a Con Artist":||"Use or Be Used":||"A Line From the Past":||"Trashy Little Tramp":||"Dead Scratch":|
|Appears||Appears||Appears||Appears||Appears||Credit Only||Credit Only||Appears||Appears||Appears||Appears|
Season 2: (17/22)
|Dynasty: Season 2 (17/22)|
|"Twenty-Three Skidoo":||"Ship of Vipers":||"The Butler Did It":||"Snowflakes in Hell":||"Queen of Cups":||"That Witch":||"A Temporary Infestation":||"A Real Instinct for the Jugular":||"Crazy Lady":||"A Champagne Mood":||"The Sight of You":|
|Appears||Appears||Appears||Appears||Appears||Credit Only||Appears||Credit Only||Appears||Appears||Appears|
|"Filthy Games":||"Even Worms Can Procreate":||"Parisian Legend Has It...:||"Motherly Overprotectiveness":||"Miserably Ungrateful Men":||"How Two-Faced Can You Get":||"Life is A Masquerade Party":||"This Illness of Mine":||"New Lady in Town":||"Thicker Than Money":||"Deception, Jealousy, and Lies":|
|Credit Only||Credit Only||Credit Only||Appears||Appears||Appears||Appears||Appears||Appears||Appears||Appears|
- In the original series, Jeff and Fallon develop a strong relationship very quickly and are soon married. Jeff also had a kind relationship with Blake, who thought of him as a son.
- The "new" Jeff is morphed with the original Cecil Colby, who was his uncle and a strong rival to Blake. In the reboot, Cecil Colby is actually Jeff's father and not his uncle. Jeff follows his father's footsteps to get revenge.
- This Jeff Colby is shown to be bilingual, speaking excellent Yoruba and English while his original counterpart didn't know Yoruba because he wasn't of Nigerian descent.