In 1976, Colt made his acting debut as Nick in the
Berkeley Repertory Theatre production of ''
Who's Afraid of Virginia Woolf?'' and as Inspector William Holmer in the episode "Castle of Fear" of
ABC's police drama
The Streets of San Francisco. In 1978, Colt appeared as Sam Pray in "Great Expectations," the fourth episode of the short-lived
CBS legal drama
The Paper Chase, starring
John Houseman. In 1979, he appeared on the ABC drama
Family and in two episodes of
Buddy Ebsen's CBS crime drama
Barnaby Jones. He also played the role of Art Hartman in the
Nick Nolte film
North Dallas Forty. Colt received second billing in the two-hour
made-for-TV film ''
McClain's Law, broadcast in November 1981 as a pilot for the same-named police series in which Colt played young detective Harry Gates of the San Pedro, California, Police Department, whose use of modern criminology methods placed him in contrast to his older partner, Jim McClain, played by James Arness, who employed the more traditional approach. McClain's Law'' premiered some six years after the ending of Arness's former
Gunsmoke western series. based on the establishment of the
Vietnam War Memorial in
Washington, D.C. Subsequently, Vietnam veteran Colt spoke at The Wall Memorial Day 1988. Other roles in television films were as Steven Beck in
Beverly Hills Madam, Charles McLean in
Maggie, Kelly Hancock in
Mercy or Murder?, Andrew Winkler in
Guilty of Innocence: The Lenell Geter Story, and Douglas Erickson in
Deceptions. Colt was cast as Bobby Slade in
Jagged Edge (1985), as Christopher Dollanganger in
Flowers in the Attic (1987), and as Donald Cleary in
Illegally Yours (1988). His last roles in series television were in 1991 as Ross Corman in the episode "Tainted Lady" of
Angela Lansbury's CBS drama,
Murder, She Wrote and in 1995 in
Chuck Norris's
Walker, Texas Ranger, in the role of Lieutenant Lee Corbin in the episode "Whitewater, Part I." ==Psychology career==