If affirmative action in the United States has you confused, imagine what it's like in Brazil, where everything is muddier. Half a millennium of mingling by Africans, Europeans and Indians gave this New World nation a hundred faces and more colors than Crayola. (One famous national census turned up 136 terms by which Brazilians classified their complexion, from "dawn white" to "cinnamon.") The record-keepers, hoping to tidy things up, reduced the official lexicon of racial types to just five: white, oriental, indigenous, black and pardo (brown). But to this day, most Brazilians simply shrug and say they are a mixed-blooded people.

Blurry as that seems, this fluid self-image has been key to the country's identity. Now, thanks to an aggressive new brand of racial politics, the picture is about to change. That is the subject of "Brazil in Black and White," a fascinating, and disturbing, new documentary that airs on the PBS network's Wide Angle series on Tuesday, Sept. 4. (check out the trailor). It was written and produced by Adam Stepan, a longtime Brazil hand, who has a keen eye for both the beauty and the beast in Brazil. The focus is the debut of "American style affirmative action" in Brazil, by way of a new Racial Quota Law and the Racial Equality Statute, which seek to implement a sweeping system of racial preferences in unversities, the civil service and the private sector. At the vanguard is the University of Brasília, which has set aside one of every five vacancies for "Afro-descendents."

Sounds fair enough. It's been almost 120 years since slavery ended in Brazil (the last country to outlaw chattel labor, by the way) but the racial chasm still runs deep. Except on the football pitch and in music, or during the few fleeting days of Carnival, precious few of the 80 million odd black and brown Brazilians ever rise to the commanding heights. Negros (blacks) and pardos spend a third less time in the classroom than do whites, earn half their wages, and are far more likely to be out of work. It's no different at the U. of Brasília, where the student body has long been white as winter.

But like most things in Brazil, this subject is hardly black and white. In a society as mottled as this one, how do you tell who is black and who is not? (Do you take their picture and ask a race committee to decide, as the universitiy does?) Is Brazil's problem one of class or racism, or both? And do preferential quotas simply bring Brazil's "invisible issue" to the surface, as Ralph Ellison might have put it, or draw a reductive color line in the sand? Watch as the camera follows the steps of five college applicants, themselves the spitting image of this kaleidescopic country, as they express their aims and their angst in full palette.