Actor. He was the son of actress Ethel Barrymore and the great-grandson (and namesake) of Samuel Colt, inventor of the Colt revolver. He appeared in four films, “The Mating Season” (1951), “A Star is Born” (1954),  “Three Brave Men” (1956),  and “Johnny Trouble” (1957). (bio by: Bobb Edwards)  Family links:  Parents:  Russell Griswold Colt (1882 – 1960)  Ethel Barrymore (1879 – 1959)  Siblings:  Samuel Colt (1909 – 1986)  Ethel Barrymore Colt Miglietta (1912 – 1977)*  John Drew Colt (1913 – 1975)* *Calculated relationship