Colvin died Thursday in North Hollywood of complications following a stroke, said his longtime friend, actress Maaren Edvard, an instructor and administrator at Michael Chekhov Studio USA West, which was founded by Colvin.
"Jack was, in every sense of the word, a consummate artist," Edvard said. "He wrote, painted and read philosophy, but he always came back to acting."
Colvin appeared in numerous TV shows, including "The Rat Patrol," "Kojak," "The Six Million Dollar Man," "The Rockford Files," "Cagney and Lacey" and "Murder, She Wrote." He also had minor roles in several films, including "Scorpio" and "Rooster Cogburn."
He had a long history as a stage actor when he was approached about the "Hulk" role in 1977. The series, based on the Marvel Comics character, aired on CBS until 1982.
"When they told me the title, I laughed. But then they gave me two scripts to read and I knew the series would go," he once told the Los Angeles Times.
In the show, as in the comic book, a lab experiment that went awry caused a mild-mannered scientist to turn into the green, muscular Hulk every time he lost his temper.
"People identify tremendously with the frustration, the rage and the anger that breaks out in a man," Colvin once said.
The actor, who once studied under Chekhov, taught the Chekhov technique at USC; California State University, Northridge; the American Academy of Dramatic Arts and the Central School of Cinematography in Rome.
He was teaching acting two days a week and working on an original play, "A Day of Jubilo," at the time of his death, Edvard said.
He had no immediate survivors. A memorial service is planned for January.