Mathew Knowles and Tina Knowles (now Tina Knowles Lawson) at a fashion show in Beverly Hills, Calif., in February 2007. (Matt Sayles/AP)

Racism is a common topic in the mainstream media. But an insidious cousin, colorism, gets less attention. Novelist Alice Walker defined colorism in a 1982 essay as “prejudicial or preferential treatment of same-race people based solely on their color.” In other words, it’s the concept of prejudice within a race against someone because of their skin tone.

It’s a particularly important and controversial topic in the music industry, where many think light-skinned artists have an edge over their darker-skinned counterparts.

Most recently, Mathew Knowles, Beyoncé’s father, former manager and a professor at Texas Southern University, decided to use his celebrity in an attempt to highlight the issue of colorism — even if it meant exposing an unpleasant truth about his past.

He recently gave an interview with Ebony to discuss his book “Racism: From the Eyes of a Child,” in which he admitted that when he was a young man, deeply ingrained colorism led him to only date white or light-skinned black women who appeared white.

He was born in 1952 in Gadsden, Ala., a small city about 60 miles northeast of Birmingham. Knowles said his experiences in the South led to his prejudice against dark-skinned black women, even though he is black himself.

“When I was growing up, my mother used to say, ‘Don’t ever bring no nappy-head Black girl to my house,’ ” Knowles told Ebony. “In the Deep South in the ’50s, ’60s and ’70s, the shade of your Blackness was considered important. So I, unfortunately, grew up hearing that message.”

At Fisk University, a historically black school, “they had a colorism issue.  . . . I was in the last class where they’d take out a brown paper bag, and if you were darker than the bag, you could not get into Fisk,” he told Ebony.

Knowles said he “used to date mainly White women or very high-complexion Black women that looked White.”

When he met Tina, she appeared white to him, he said, which is why he began dating her. “I actually thought when I met Tina, my former wife, that she was White. Later I found out that she wasn’t, and she was actually very much in-tune with her Blackness.”

“I had been conditioned from childhood,” he said. “With eroticized rage, there was actual rage in me as a Black man, and I saw the White female as a way, subconsciously, of getting even or getting back. There are a lot of Black men of my era that are not aware of this thing.”

Knowles and Tina Knowles Lawson were married for 31 years, divorcing in 2011. They issued a statement at the time that said, “The decision to end our marriage is an amicable one. We remain friends, parents, and business partners. If anyone is expecting an ugly messy fight, they will be sadly disappointed.”

Knowles said he shared his story in the hope that others would consider colorism, which he implied is commonplace in the music industry.

“When it comes to Black females, who are the people who get their music played on pop radio?” Knowles said. “Mariah Carey, Rihanna, the female rapper Nicki Minaj, my kids [Beyoncé and Solange], and what do they all have in common?”

The answer is that they have lighter skin.

Before Knowles spoke out, debate around colorism in music was already raging after VH1 highlighted the problem in their reality show “Love & Hip Hop Miami,” which debuted in January.

In the first episode, Afro-Latina singer Amara La Negra wants to break into the American music market. La Negra, who is of Dominican descent, enlists the help of producer Elijah “Young Hollywood” Sarraga.

Sarraga said he thought La Negra is talented, but he was hesitant to work with her because she needs to “look a certain way . . . a little bit more Beyoncé, a little less Macy Gray.” Sarraga, who is also Latino, continued to demean and belittle La Negra’s identity. At one point he called her a “Nutella Queen,” comparing the color of her skin to the chocolate-hazelnut spread.

VH1 received backlash online for the show. But the show’s creator, Mona Scott-Young defended the decision, telling the Grio website she wanted people talking about the issue because “if you aren’t talking about something how can you be fostering understanding?”

Scott-Young also said if we don’t give the subject a platform, “we will never see change.”

Others have used their platforms to tackle the topic. A few years ago, for example, J. Cole, one of the world’s most popular rappers, said he doesn’t think he would be quite as successful if he had darker skin. Nor does he think President Barack Obama would have won the presidency if he had darker skin.

“That brainwashing that tells us that light skin is better, it’s subconsciously in us, whether we know it or not,” the rapper told BET in 2013. “But Barack Obama would not be President if he were dark skin. You know what I mean? That’s just the truth. I might not be as successful as I am now if I was dark skin.”

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