Lupita Nyong’o, the Academy Award-winning actress and voice of Maz Kanata in “Star Wars: The Force Awakens,” will write her debut children’s book “Sulwe” for Simon & Schuster Books for Young Readers next January. The picture book is aimed at readers between the ages of 5 and 7. An illustrator has not yet been announced.

“Sulwe,” which means “star” in Ms. Nyong’o’s native language, Luo, is the story of a 5-year-old girl growing up in Kenya. In the book, Sulwe has the darkest skin color in her family, a fact that makes her uncomfortable and determined to find a way to lighten her skin. As the story unfolds Sulwe embarks on a whimsical adventure in the night sky that, coupled with advice from her mother, helps her see beauty differently.

For Ms. Nyong’o, the decision to touch on these heavy and often difficult themes in a children’s book was obvious. The story plants seeds in a child’s mind, allowing for later access to lessons that children “don’t necessarily recognize when they are reading the books,” said Ms. Nyong’o in an interview. When thinking about her own journey into acceptance and self-love, Ms. Nyong’o cited reading with her mother as critical to her development.

Like Sulwe, Ms. Nyong’o struggled with her complexion and self-image as a child. Growing up, she remembers becoming more aware of herself in grade school and caring about the opinions of others. It was around that time that she also noticed the language people outside of her family used to describe her “brown and pretty,” lighter skinned sister.