During the past 20 years, television and the movies have taken on more color as non-whites have found more work in film, situation comedies and TV commercials.

Black, Latin and Asian Americans are now serving mass media's good-natured indulgence in ethnic humor just as Jewish and Italian Americans have been doing for years.

"Chico and the Man" brought us the light-hearted cleverness of the Puerto Rican-Chicano."Good Times" shows us poor-but-honest blacks smiling through hardship. And "The Jeffersons" assure us that even success won't spoil black folks for comedy. Even-handedly, television balances the bigotry of Archie Bunker with that of Fred Stanford.

Movie moguls, too, since the 1960s, have discovered a commercial potential in Afro-American subjects.

While most have been "blaxpolitation" films like "Superfly" and "Shaft," some, like "Sounder" and "Cooley High," were honest and thoughtful efforts to portray black life. One film, "Ganja and Hess," was even exceptionally good cinema.

Black superstars are in the commercial entertainment galaxy. It was a historic event when, in 1939, Hattie McDaniel won an Academy Award for best supporting actress in "Gone With the Wind" and when, 24 years later, Sidney Poitier won an Oscar for best actor in "Lilies of the Field." Perhaps it is a sign of some change that we would not consider such honors to black performers quite so remarkable today.

It would appear we are a far cry from the pre-1960s when, fearful of offending southern white audiences, the television and movie industries flagrantly pandered racial bigotry. Some of these apparent changes regarding minorities and the media are real, but we must remind ourselves that mass media are purveyors of illusions, and the changes we see are likely to be far less than what we get.

Certainly there are more nonwhites on television today, but thoughtful treatment of ethnic life and issues is rare. Situation comedy will trivialize anything. Intermarriage in "The Jeffersons" is reduced to mere idiocy. Chronic underemployment for urban blacks is given no better treatment in "Good Times."

Of course, it is good to have a sense of humor and be able to laugh at ourselves, but the media generally give us nothing else.

It is pleasing, nevertheless, to see nonwhite performers making it in an industry dominated and defined by whites. Between TV commercials and one or two superstars, more money is going to nonwhite talent now than a few years ago.

We should not imagine, however, the plight of the minority artist has improved markedly in the last 20 years. Marketing and advertising men who run Hollywood prefer known personalities (from whatever background) to committed artists. Hollywood has "discovered" pitifully few black performers.

It tends rather to draw "stars" who have already made their mark on the football field, the nightclub circuit, Las Vegas and all too seldom the theater.

The superstar, once "made," tends to define the limits of major films about minority subjects. Producers of costly film projects need a superstar in the "package" to have any hope of raising money. Thus, to make "The Wiz," it was thought better to choose Diana Ross to play the 12-year-old Dorothy than teen-ager Stephanie Mills, who made the Broadway musical a spectacular success. Miss Ross can be packaged and sold as a commodity more easily than a highly talented youngster.

For every O.J. Simpson, Jim Brown, Fred Williamson, and Diana Ross, there are thousands of trained and talented professional actors and actresses who do not possess a celebrity that Hollywood can market. Until they make it big somewhere else, they are, with a few exceptions, not likely to find much success in film or television. White performers have some of these same problems, but there are far more roles and far more productions open to them.

Members of minorities - with a few exceptions such as Sidney Poitier - have not moved into the media industries in positions of producers, writers, or directors where they could affect programs. Those few who are producers and directors have almost no chance to choose or shape the character of their vehicles.

The handful of writers who find work are viewed with suspicion whether they write about their own minority (they are presumed to have an ax to grind) or whether they attempt something general (they are not supposed to know about white folks).

Black writers are lucky to succeed at all in film and television despite increased portrayal of Afro-American subjects. Even the phenomenal television production of "Roots" - using several writers and directors - employed no black writer; a black director was given the chance to do just one episode.

White in the industry remain exclusive judges of what is suitable for viewing. They, in effect, define whatever ethnic content will get aired. Small wonder there is little authenticity in minority representation in the media.

It takes a lot of money as well as command of an industrial apparatus to produce movies and television. A modest estimate for a half-hour television show is $250,000. "Rocky," "a low-budget film," cost only $1.1 million. Such costs act as an effective censor to minority producers.

And things are hardly better in public broadcasting. It suffers serious budget limitations, and, like commercial television, the public network and stations find the Federal Communications Commission's "fairness doctrine" - obliging stations to grant equal time when one side of a controversy is aired - a sufficient reason to reject most programs that might have meaning to minorities.

At least television news has allowed minorities to bring their grievances before the public. The cause of such groups as freedom riders and marchers and Cesar Chavez' farm workers have been brought into the home. Leaders like Martin Luther King and Stokely Carmichael, accused persons like Bobby Seale, Angela Davis and Joanne Little, gained a national audience through television news broadcasting. We assume media exposure gained them sympathy and support.

But media exposures has cut both ways. The cameras recorded the White Backlash as eagerly as Black Power. They transmitted the riots in South Boston as quickly as the march on Washington.

They broadcast the sentiments of the white, Pontiac, Michigan, housewife protesting "forced busing" as earnestly as they had the achievement of Mrs. Rosa Parks in the Montgomery bus boycott.

Any group willing to make a display, break the public peace, engage in civil disobedience will catch the camera's eye and be carried into the homes of America. Few things short of disorder, however, will have broad media impact. And minority demonstrators have paid a higher price, in the way of jailings, beatings, and killings, than have their white counterparts.

Many do not share my pessimism about the media.Others find more substance in the images than I do. They detect there evidence of minority success and achievement, symbolic of their "rising expectations."

I am impressed rather with the reality of unemployment touching as much as 25 percent of black and minority youth of working age, of generations trapped in a hopeless welfare system, of a general retreat from social programs initiated in the 1960s. Vast numbers of parents have expectations that rise no higher than getting or holding a job, receiving a welfare check or food stamps, keeping their kids off drugs, reasonable heat and garbage removal, and police protection without brutality.

The realities are rather dreary for the poor, the old, and the nonwhite in America.

But many of us can avoid touching the centers of this plight. Automobiles transport us around the ghettos, and mass media give us images of easy optimism. Therefore, only a persistent skepticism of manufactured illusions will keep us in touch with our reality.

Nathan Irvin Huggins is professor of history at Columbia University. Formerly president of the Museum of Afro-American History in Boston, he has been a member of the board of advisers for Children's TV Workshop since 1970. He is author of "Protestants Against Poverty" and "Harlem Renaissance," and co-editor of "Key Issues of the Afro-American Experience."

This is the 12th in a series of 15 articles exploring "Popular Culture Mirror of American Life." This series was written for Courses by Newspaper, a program developed by University Extension, University of California, San Diego, and funded by a grant from the National Endowment for the Humanities.