If the demographers are correct that Latinos will be a majority in California by 2042, filmmaker Phillip Rodriguez has a question: “Who are these new neighbors?”

CLAUDIA ROCHA Comedian George Lopez learned to "walk a tightrope between ethnic authenticity and prime-time appeal," according to a new documentary.

He searches for answers in his documentary, “Brown is the New Green: George Lopez and the American Dream,” which airs Thursday, on KPBS. The hour-long film explores the way Latinos are perceived by the media and marketers – and how they perceive themselves.

“Americans are in a collective state of confusion about Latinos,” Rodriguez said.

He's not surprised. It starts with terminology. Most Latinos don't call themselves Latino; they are more likely to identify themselves by their country of origin. Hispanic? That's a term the federal government came up with for record keeping.

And it's a myth, Rodriguez said, to consider Latinos a homogenous group.

“What are the commonalities between a member of the Cuban bourgeois who came here in 1959, and a peasant from Michoacan who came here yesterday?” he asked during a phone interview from Los Angeles, where he lives. “Other than language, and maybe Catholicism, I'm not sure there are many.”

DETAILS “Brown Is the New Green” A documentary about how Latinos are perceived by the media and marketing companies. When: Thursday, 9 p.m. Where: KPBS / Channel 15

Yet as his documentary shows, many media and marketing companies continue to treat Hispanics as monolithic, and that in turn is shaping how America understands the nation's largest (44 million) and fastest-growing ethnic group.

Or doesn't.

“Latinos are caught in a netherworld,” Rodriguez said. “Mainstream media have largely ignored them, while Spanish-language networks and Hispanic ad companies have served up an exoticized image that has no basis in contemporary American reality.”

One notable exception is comedian George Lopez, he said. Before being canceled this year after five seasons, “The George Lopez Show” was the longest-running English-language program with a Latino lead in TV history.

The documentary starts with footage of Lopez heading to a stand-up comedy appearance – first in a helicopter, then a limousine. He's arrived, in more ways than one.

Talking about his popularity, Lopez says: “Finally there is someone that you can invest in that looks like you, speaks like you, relates to things you relate to, and makes our culture OK to talk about.”

CLAUDIA ROCHA Filmmaker Phillip Rodriguez (left) with Lopez following the comedian's performance at the Long Beach Arena.

Rodriguez likened Lopez to Bill Cosby, whose 1980s sitcom “normalized” African-American life for a wider audience. Lopez, he said, “is a case study of someone who managed to introduce this brown Mexican-American identity to mainstream audiences.”

By following Lopez around – to his stand-up act, to a sitcom writer's meeting, to the set of the show – the film addresses an important question, Rodriguez said: “How does an outside culture get on the inside?”

Cosby's show was criticized in some quarters as too bland; Lopez, too, has been accused of sanding off some of his sharp edges. He doesn't deny it.

“I've been in meetings with Warner Bros. when I wasn't particularly happy with what I was hearing,” Lopez recounts in the documentary. “The Chicano in me would say, 'I'm leaving.' But when you leave, you're out. So I made myself stay. Probably a lot of people would say that's selling out. But it's not selling out. It's the way the business is set up.”

“Brown is the New Green” also explores the way another business is set up – marketing. As the Latino population in the U.S. grows, so does its buying power. According to economists at the University of Georgia, Hispanics will account for about 10 percent of all U.S. buying power by 2011, up from 5 percent in 1990.

Advertisers chasing those dollars have to decide whether to continue treating Latinos as separate, Rodriguez said, or as part of the mainstream.

Several Hispanic ad executives are interviewed in the documentary, and they seem to favor the status quo. “It's our audience to win,” one of them says. “It's our hill to keep.”

But the film raises doubts about whether catering to “cultural otherness” will work in the long run. Latino teens are asked about their favorite television shows; contrary to what many people might believe, they aren't watching a lot of Spanish-language programming. Instead, they mention shows like “24,” “Real World” and “South Park.”

In the documentary, Lopez says his TV show succeeded because it wasn't overtly Mexican. His sitcom family was an American family first, with ethnic layers added gradually. He resisted studio executives who thought the show's kitchen wasn't Mexican enough. (They wanted to add a tortilla machine.)

Similarly, during auditions for the show, some actors used heavy accents, thinking that would make them sound more authentic. Lopez told them to use their normal voices.

He thinks advertisers should adopt the same approach. “Just include us in the faces that you see buying a Maytag,” he says. “Don't make a Maytag Mexican commercial.”

Rodriguez, the grandson of Mexican immigrants, agreed. “We came here not to be separate, but to be part of the American project,” he said. “Appeal to that aspiration of ours. Don't give us the rearview mirror. That's why we left.”

Rodriguez, 47, is a senior fellow at the Annenberg School for Communications at USC. His earlier documentaries include “Los Angeles Now” and “Mixed Feelings: San Diego/Tijuana.”

The timing of his new film has raised some eyebrows. It comes 11 days before PBS begins airing Ken Burns' seven-part epic about World War II, “The War,” which has been criticized for months by Latino activists. They said the filmmaker overlooked the experience of Latinos on the battlefield and the homefront.

After initially rejecting the protests as unfair, Burns added about 30 minutes of material to his film, interviews with two Latino veterans from Los Angeles and a Native American veteran from Montana.

Rodriguez said “Brown is the New Green” was under way before the flap about “The War.” Still, he thinks PBS is eager to air his documentary first because “they had egg on their face” from the Burns controversy.

PBS is airing several other Latino projects this month, but spokeswoman Lea Sloan said it is unfair to link the scheduling to what happened with “The War.” She said PBS has long supported Latino-oriented programming.

The Associated Press contributed to this article.