The Oscar winner, 34, said the publication “edited out and smoothed my hair to fit their notion of what beautiful hair looks like,” later adding that she is “disappointed” by the final result.
Along with her lengthy statement on Instagram and Twitter Thursday, the actress also shared the unedited photos.
Grazia UK has yet to make a statement following Nyong’o’s claim.
“As I have made clear so often in the past with every fiber of my being, I embrace my natural heritage and despite having grown up thinking light skin and straight, silky hair were the standards of beauty, I now know that my dark skin and kinky, coily hair are beautiful too,” Nyong’o said.
“Had I been consulted, I would have explained that I cannot support or condone the omission of what is my native heritage with the intention that they appreciate that there is still a very long way to go to combat the unconscious prejudice against black women’s complexion, hair style and texture,” she concluded.
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This is not the first time a magazine has been accused of photoshopping Nyong’o’s appearance.
In January 2014, Vanity Fair was slammed online from readers and social media users who said Nyong’o’s dark skin looked noticeably lighter.