Mexican airline Aeromexico has become embroiled in controversy after posting job vacancies for a commercial that stipulated "dark-skinned" people would not be allowed to audition. 

The casting call sought those with a "Polanco look," referring to a well-to-do white neighborhood in Mexico City. A photo of the casting e-mail was taken by Mexican blogger Tamara De Anda, who expressed her frustrations about how the representations of brown people in Mexican media largely do not exist outside of government program announcements.

On Twitter, De Anda posted, "I received an email for a casting call from Aeromexico specifying that they don't want anyone dark-skinned. Tsss."

About 400 retweets later, the story gained traction on social media. With a population of 20 million, Mexico City's racial makeup consists of 60 percent mestizo (Amerindian-Spanish); 30 percent Amerindian or predominantly Amerindian; 9 percent white; and 1 percent other, according to The World Factbook.

The airline pointed to an ad agency, Catatonia, and subsequently issued an apology for the language on Twitter, stating, "We're sorry for Catatonia's discriminatory stance, that was circulated today on social media. We offer our sincerest apology and reiterate our respect for all people, no matter their gender, language, religion, nor their skin color."

Catatonia expressed regret, according to Fox News Latino, stating it "offers a heartfelt apology for the publication on casting requirements that circulated on social networks."

Perceptions of skin color and discussions of racism have long been a subject of debate in Latin America.

Meanwhile, a recent paper by Felipe Lopez and James Vigil of The Journal of Latino-Latin American Studies suggests research is beginning to reexamine the conventional wisdom in Mexico that a "mestizocracia" reflects the nation's racial and cultural heritage, and not the separation that exists between urban "European-appearing" elites and Indians or darker mestizos from a low income background.

Challenging the common belief that race problems and racism were solved over a hundred years ago in the aftermath of the colonial era, this paper explores some of the key issues in the debate and shows that there are still many entrenched racist attitudes and practices that persist from that time period, affecting both Mexicans in Mexico and the United States.

The creation and promotion of a mestizo ideology by government officials is offset by the recent surge of racial pride and ethnic nationalism among Indians, particularly in light of the Zapatista movement. National "identity" politics include psychological elements and intra-group racism denoting the striving for a positive self-image.

In a 2012 opinion piece for CNN, Ruben Navarrette Jr. examined the issue, writing, "On television, in politics and in academia, you see light-skinned people. On construction sites, in police forces and in restaurant kitchens, you're more likely to find those who are dark-skinned."

"In the priciest neighborhoods, the homeowners have light skin, and the housekeepers are dark. Everyone knows this, and yet no one talks about it, at least not in elite circles," he wrote.

The enduring taboo subject is skin color, whether an individual's complexion betrays an allegiance to the Spanish who conquered the Aztec empire in 1521 or the Aztecs who were conquered. It's no exaggeration to say that, in this country and especially in this city, the best, highest-paying, most important jobs often seem to go to those who, in addition to having the best education and the strongest connections, have the lightest skin. Everyone knows this, and yet no one talks about it, at least not in elite circles.