NEW YORK (AP) — One of Idris Elba’s grandfathers fought in World War II, but he doesn’t know what he endured. No pictures or stories survive. “That part of my family’s history has been erased somewhat,” says Elba. That helped fuel the actor’s push to narrate and executive produce the four-part National Geographic docuseries “Erased: WW2’s Heroes of Color,” which premieres Monday, days ahead of the 80th anniversary of D-Day, when the Allies landed on the coast of France, on June 6. Episodes will also later be available on Disney+ and Hulu. More than 8 million people of color served...