The universe of “Black-ish” has become as expansive as “Game of Thrones.”

The ABC sitcom — soon entering its sixth season following the fictional Johnson family —has spawned two spinoffs: Freeform’s “Grown-ish,” which follows Johnson daughter Zoey (Yara Shahidi) through college, and now ABC’s “Mixed-ish.”

Premiering Tuesday at 9 p.m., “Mixed-ish” follows “Black-ish” matriarch Rainbow Johnson (Tracee Ellis Ross) through her eccentric childhood in the ’80s (young Rainbow is played by Arica Himmel).

“Fans who liked ‘Black-ish’ hopefully will tune in and feel it’s still in the same universe, but we also want to open up the audience to any new viewers,” says “Mixed-ish” showrunner Karin Gist, 47, whose previous works include “Girlfriends” and “Revenge.”

“The show is trying to focus on the human experience and inclusion and identity across the board.”

The first episode opens with Ross and the rest of the “Black-ish” Johnson family before flashing back to Rainbow’s childhood. The rest of the show after the pilot is firmly rooted in the 1980s — but Ross (who’s also an executive producer) lends her voice as a narrator throughout.

Also lending her voice to “Mixed-ish” is pop superstar Mariah Carey, who sings the show’s opening theme.

“She’s a big fan of ‘Black-ish’ and ‘Grown-ish,’ and when she saw that ‘Mixed-ish’ was a thing, she was compelled to reach out to [creator Kenya Barris],” says Gist. “Because she couldn’t believe this story was being told, it’s such a personal story for her. So she asked to be part of the project and just wrote this amazing song.”

‘It’s about the human experience of finding your voice and creating your own identity.’

As Rainbow’s name suggests, her parents — played by Mark-Paul Gosselaar (“NYPD Blue”) and Tika Sumpter (“Gossip Girl”) — are hippies. The show chronicles Rainbow’s childhood in a cult-like commune and her harsh awakening once her family moves to the California suburbs — young Rainbow, enrolling in a traditional school for the first time as a pre-teen, isn’t used to the latest fashion, the latest slang or virtually any social structure. She also doesn’t understand what it means to be “mixed race” until other students at the school tease her about it.

“When viewers tune into our show, we want to make it clear that it’s about Rainbow’s specific experience as a biracial girl in 1985,” says Gist. “But we want the story to speak to anyone who feels ‘other.’ It’s about the human experience of finding your voice and creating your own identity.”

Gist says it wasn’t difficult navigating the “Mixed-ish” world amidst its two sister shows on ABC and Freeform.

“We don’t really coordinate, but of course all the writers in the ‘Mixed-ish’ room have seen ‘Black-ish,’ ” she says. “ We also have a cheat sheet of facts that have been established on ‘Black-ish.’

“But we want ‘Mixed-ish’ to stand on its own.”