Coles has appeared on many television shows, including Frasier (where she became known for playing "Dr." Mary Thomas), Six Feet Under, Celebrity Mole and The Geena Davis Show. She is perhaps best known for her roles on two FOX series; first as an original cast member of the sketch comedy series In Living Color, then as Synclaire James on the sitcom Living Single and as the mother of Spirit on One on One. Coles is a published author; her book is called I'm Free But It Will Cost You, ISBN 978-0786883226, Hyperion Books, 1998.

Coles appeared on Celebrity Mole: Hawaii and was the first contestant to be eliminated. At the reunion of the show, she was one of two celebrities (the other was Michael Boatman) to correctly guess that Frederique van der Wal was the series' saboteur, Kathy Griffin was the winner, and Erik von Detten was the runner-up. Coles also joined other celebrities for a weight loss journey on the VH-1 reality show, Celebrity Fit Club.