P.O.V. is kicking off its fifth season with Marlon Riggs’ new film, Color Adjustment, which traces the history of black entertainment on TV from Amos ‘N’ Andy to The Cosby Show.

As written and directed by Riggs, this is a conventional, studiously uncontroversial project, with well-chosen clips plus commentary from critics and sociolo-gists. At one point, the first-rate literary critic Henry Louis Gates Jr. drops his academic facade and cheerfully confides that Bill Cosby’s Rhodes-scholar globetrotter character in I Spy was ”my idol.”

What’s lacking? The very thing that supposedly qualifies the film for inclusion in this series: a point of view. Riggs shows us scenes from shows like The Jeffersons and Roots and Cosby and superimposes over them the printed question, ”Is this a positive image?” Well, what’s your opinion, Marlon — is it or isn’t it? Still, Color Adjustment is a smart way for P.O.V. to begin its new season — all those familiar faces from commercial TV, added to Riggs’ notoriety, will almost certainly attract more viewers than the average P.O.V. entry. B-