Junot Díaz says children’s books lack diversity. He hopes his will help change that.

Twenty years ago, novelist Junot Díaz promised his goddaughters he would write a children’s book for them. Their request: to see people like them — Dominican girls living in the Bronx — in its pages.

The girls are no longer girls but their book is finally here. On Tuesday, Díaz, best known for his Pulitzer Prize-winning novel “The Brief Wondrous Life of Oscar Wao,” published “Islandborn.” As promised, it is a picture book that features Dominican girls living in the Bronx. The story centers on a young girl named Lola who sets out to collect memories of the Dominican Republic she left as a baby.

Like Lola, Díaz was born in the Dominican Republic; he immigrated to the United States when he was 6. The book, he said in a phone interview from his home in Cambridge, Mass., “started with an observation — that the narrative of innocence that hangs over a lot of children’s books was insufficient to address the kind of childhood that I had, and also the people in my life. There is this very adult idea that children have to be protected or that the uglier parts of life can't be brought into children's books.”

Diaz hopes “Islandborn” will help correct that. The book, which clocks in at 48 pages (most picture books are 32 or fewer) is a gem of a tale that captures the joy and hardships of life in an urban, mostly immigrant community.

“Every kid in Lola’s school was from somewhere else,” the book begins. The children’s teacher asks each of her students to draw a picture of their “first country.” Lola is at first panicked because she remembers nothing of her birthplace. But she eventually realizes that she can — literally and figuratively — draw on the many memories of the family and friends who come from her birth country, and she ends up with so much material that she creates an entire book of pictures.

Some of the memories depicted in Lola’s book are jubilant, as her neighbors, family and friends recall the sound of music and the brilliant colors of their island homeland. Other memories are much darker, because of the “Monster” who invaded the Island and ruled it for 30 years before “heroes rose up” and banished it forever. Though unnamed, it’s clearly a reference to dictator Rafael Trujillo, whose reign of terror traumatized generations of Dominicans. (Still, Díaz believes the monster can represent a wide array of fears.)

Mitigating the serious message of the book are the bright and sunny illustrations by Colombian-born artist Leo Espinosa, now based in Park City. The pages explode with vibrant hues, as Lola gathers material from her world to tell her own kaleidoscopic tale.

Díaz was thrilled with Espinosa’s work: “There’s one thing that really matters to my community, which is how slighted we have been in visual culture, and how wrongly the textures of our skin and hair are depicted. Espinosa’s art is a master class in, among other things, just the reality of our hair.”

While ‘Islandborn” (also available in a Spanish edition called “Lola”) clearly will resonate with immigrant readers, Díaz said that’s not the only audience for the book. “The best stories provide us with opportunities for recognition and estrangement — to be spoken to most directly, or to feel that we are eavesdropping.”

Díaz, a professor at MIT and a recipient of the MacArthur “genius grant,” hopes his book will help change the landscape of books children are offered in school and at home.

“It’s only the grim racial policy in a nation like ours that predisposes white children to only imagine white children as their narrative analogues,” he explained. “If kids of color can read about white characters in children’s books all day, the only thing preventing the reverse is a malign set of racial policies,” he says. “The white default is, in some ways, the cornerstone of white supremacy. It's not some innocent issue.”

For Díaz, though, the true test of how well he did in writing “Islandborn” came when he finally presented a copy to his oldest goddaughter, “a tough cookie” now in her late 20s.

“I realized I had gotten my passing grade when she read the book, then put it down and wept.”

MacPherson is the children's and teen services coordinator for the Takoma Park, Md., library.