Lupita Nyongo addressed the long history of colorism in a powerful string of tweets on Monday.

The Oscar-winning actress wrote that societys preference for lighter skin, is alive and well, noting that colorism is not just a prejudice that exists in places with a largely white population.

Throughout the world, even in Kenya, even today, there is a popular sentiment that lighter is brighter, said Nyongo, who was born in Mexico City and raised in her parents native Kenya.

The Us actor tweeted a photo of herself at 5 years old, writing that her fantasies as a child motivated her to write Sulwe, her newly released childrens picture book about colorism and self-love that centers on a dark-skinned girl.

As a little girl reading, I had all of these windows into the lives of people who looked nothing like me, chances to look into their worlds, but I didnt have any mirrors, Nyongo wrote, adding that mirrors help us develop our sense of self, and our understanding of our own world.

Nyongo has addressed colorism and its impact on communities on numerous occasions.

In a 2014 interview with Glamour, Nyongo said that European standards of beauty plague the entire world.

The idea that darker skin is not beautiful, that light skin is the key to success and love, she continued.

In 2017, Nyongo criticized Grazia UK for featuring an altered image of her hair on its cover. The actor pointed to a long history of discrimination against Black hair and Black hair textures.

Disappointed that @GraziaUK edited out & smoothed my hair to fit a more Eurocentric notion of what beautiful hair looks like, Nyongo tweeted that year .