The fall television season introduced some new faces in old formulas: “Julia,” which premiered in September, was thin dramatic fare, but it came with Diahann Carroll, television’s first true black star who did not simply receive co-billing or play in eye-rolling comedy. “Julia” went on against the long-feared “Red Skelton Show” and survived. The new “Adam 12” was decidedly square and derived from real cases like its television ancestor “Dragnet,” while the other two premiering cop dramas tinkered with the established form: “The Mod Squad” had three stars all under thirty, who never appeared in uniform. The trio infiltrated groovy enclaves like colleges or motorcycle gangs—places where crew-cut cops couldn’t follow, but where Clarence Williams III, in his bold Afro, and the ever-miniskirted Peggy Lipton, shaking her hair from her eyes, blended effortlessly. “Hawaii Five-O” made something exotic and lush of the standard detective drama. Its cool star, Jack Lord, commanded in dark suits and blue-black hair. The smugglers and drug dealers who despoiled his paradise rarely got away before he delivered his satisfying tag line, “Book ‘em, Danno,” at the end of the hour.