Lupita Nyong'o is adding author to her resume with a powerful children's book about self-acceptance -- drawing inspiration from her own childhood.

The Academy Award-winning actress told "Good Morning America" that seeing people with light skin on TV and in books effected her self-esteem as a young girl.

"It made me feel uncomfortable with my skin color," Nyong'o said.

Nyong'o said she'd often hear her younger sister, who had lighter skin, being told how pretty she was.

"I realized that it was in the omission of those words when it came to me, that made me feel unworthy and so it took a while for me to find my stride and learn to love the skin I'm in," she said. 

"I wrote this book to help little kids get there a little faster," she added.

"Sulwe," which means "star," is the main character in Nyong'o's book. Sulwe has "skin the color of midnight," but wants a lighter complexion. The little girl goes on a journey which opens her eyes to self-love and recognizing her own, unique beauty.

Nyong'o said growing up, she admired books like Cinderella and Rapunzel where the main characters often had light skin and blonde hair.

"[I] thought that in order to make it into the pages of books, you had to be light," she said. "In fact, one of the first times I drew my family, I drew them with light skin. I used the cream-colored crayons and not the dark ones because I just didn't see that in books. I didn't think we belonged in books." 

"I wrote this to give dark-skin kids a chance to live in the world of imagination and magic," she said. Nyong'o said her 2018 role in the film "Black Panther" also enticed her to write "Sulwe."

VIDEO: Lupita Nyong’o shares powerful story behind new children’s book, ‘Sulwe’
VIDEO: Lupita Nyong’o shares powerful story behind new children’s book, ‘Sulwe’

"Black Panther was a movie that was imaginative... it dealt with some really serious issues but in a fly and fun way and so that's when I had my ah-ha moment and I was like, 'Yes, this is the way I would like colorism to be experienced. I want for kids to love the book when their younger, and then grow up to understand it later,'" she said.

Nyong'o ended her visit at "GMA" by reciting her favorite Dr. Seuss quote to a group of children in the audience: "Today you are you. That is truer than true. There's no one alive that is you-er than you. So be the best you, you can be."

"Sulwe" is available now.

"Black Panther" is produced by Disney, the parent company of ABC News.