She may be best known for her television roles as roller-skating carhop Marsha Simms on Happy Days and as Etta Candy on the first season of Wonder Woman.
[5] She was the first actress to portray Etta Candy in the live action adaptation of the DC comic book series Wonder Woman.
Her final television appearance before retiring was in a 1997 episode of Nickelodeon's The Secret World of Alex Mack.
[10] She died of lung cancer, which metastisized to a brain tumour years later, on November 18, 1999, in Los Angeles, California, at the Cedars-Sinai Medical Center.
[10][11] Colen died on the opening night of Brentwood High School's production of The Man Who Came to Dinner, which was written by her grandfather, Pulitzer Prize-winning playwright George S. Kaufman, and which starred her son, James, in the title role of Sheridan Whiteside; James honoured her wish that he perform that night.