(CNN) It doesn't matter what skin tone you're trying to portray. Blackface, brownface, yellowface, redface. Any colored-face you wear that isn't yours is racist.

Here's why these incidents and others like them are so offensive.

They have a long, painful history

The first minstrel shows depicted black people as lazy, ignorant, cowardly or hypersexual.

Negative representations of non-white people date back to the mid-19th century . White actors performing in minstrel shows would darken their skin with polish and cork to look stereotypically "black."

The shows were intended to be funny to white audiences, but they were hurtful and demeaning to African-Americans because they reinforced white people's notions of superiority.

"By distorting the features and culture of African Americans -- including their looks, language, dance, deportment and character -- white Americans were able to codify whiteness across class and geopolitical lines as its antithesis," says the Smithsonian's National Museum of African American History and Culture.

The characters were so widespread that even some black performers wore blackface, historians say, as it was the only way they could work. White audiences didn't want to watch black actors do anything but look foolish on stage.

They perpetuate dehumanizing stereotypes

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Portraying yourself as someone of a different race is not just a representation of a person but rather using someone's skin tone as a costume.

Hollywood, for example, has faced backlash for characters' representations of different racial and cultural backgrounds.

Asian. They were in yellowface and wore stereotypical Asian attire. Some viewers were outraged and called the show out on Twitter with the hashtag #HowIMetYourRacism. A "How I Met Your Mother" episode from January 2014 recast three of its actors, all white, to beAsian. They were in yellowface and wore stereotypical Asian attire. Some viewers were outraged and called the show out on Twitter with the hashtag #HowIMetYourRacism.

One of the co-creators, Carter Bays, acknowledged that some people didn't find the episode funny and apologized on the show's behalf.

"We try to make a show that's universal, that anyone can watch and enjoy," Bays tweeted . "We fell short of that this week, and feel terrible about it."

They show the larger problem of identity politics

A government ad in Singapore featured an actor dressed as characters of different races.

Despite the number of controversies, there are still claims of ignorance. And it's not just seen in western countries.

A Chinese actor who allegedly darkened his skin to portray characters of different races in a government advertisement for electronic payments sparked a brownface controversy in July 2019 in Singapore , a country know for its multi-ethnic population.

The agency hired to create the ad and the city state broadcaster's talent management group apologized and said that the ad was intended to show how e-payment was for everyone.

"For that reason, Dennis Chew, well-known for his ability to portray multiple characters in a single production in a light-hearted way, was selected as the face of the campaign," Havas Worldwide and The Celebrity Agency (TCA) said in a joint statement to CNN. "He appears as characters from different walks of life in Singapore, bringing home the point that everyone can e-pay."

Cases of blackface, brownface, redface and yellowface have involved people from different social statuses, including celebrities, college students and elected officials.