The gilt frame that surrounds the proscenium of the San Francisco War Memorial Opera House is the first indication you’re about to see a story centered on two of the most significant artists of the 20th century.

But you won’t find projections or high-tech re-creations of work by Mexican paintersFrida KahloandDiego Riverain“El último sueño de Frida y Diego”(“The Final Dream of Frida and Diego”), the new opera by Bay Area composer Gabriela Lena Frank and librettist Nilo Cruz at San Francisco Opera.

“We went back to the aesthetics of painting,” said the opera’s director, Lorena Maza. “The frames are part of that two-dimensional aspect of painting, especially in Frida’s case. It was a really conscious decision not to use technology for this set and to really try to reproduce these painting-like images.”

Throughout “Frida y Diego,” which had itsBay Area premiere Tuesday, June 13, frames recur as set devices, further establishing the surreality of both the opera itself and of Kahlo’s signature style. Maza and her production team knew they didn’t want to reference the “typical cliche folkloric Mexican popular art” they felt all too common. This was especially important in how the production embodied its title couple.

Rivera,played by baritone Alfredo Daza, was an acclaimed muralist famed for his leftist politics. Among his works are three murals he painted in San Francisco in the 1930s and ’40s. Kahlo, portrayed by mezzo-soprano Daniela Mack, is globally celebrated for her self-portraits. In addition to painting several works during her trip to San Francisco with Rivera in 1931, she also exhibited her work at the Legion of Honor and the World’s Fair on Treasure Island in 1940, where Rivera was creating his mural“Pan American Unity.”

While Rivera’s murals made him more famous in their lifetimes, Kahlo’s deeply personal depictions of herself, with her full eyebrows and wearing regional Mexican fashion, have since made her a feminist icon. Because of that, the opera’s creative team knew they wanted to go beyond the images of and by the couple that have been emblazoned on everything from T-shirts to tote bags. (The two were also the subject of the 2002 film “Frida,” starring Salma Hayek and Alfred Molina.)

“感谢上帝,这不是一个传记,它s a fictional allegory of their last encounter,” Maza said of the co-commission by San Francisco Opera and San Diego Opera. “That helps in allowing us to (create) a universe for this story. But their iconography is so known, so exploited, that was our main challenge.”

“El último sueño de Frida y Diego” takes place on Dia de los Muertos (Day of the Dead) in 1957, three years after the death of Kahlo at age 47. Rivera goes to a cemetery and implores his wife to return to him in his loneliness. Aided by the Aztec deities La Catrina (from which the Day of the Dead skeleton figure derives) and Mictlantecuhtli, the pair are reunited. Questions of existence, creation and the nature of art then play out for the living and the dead.

But is the action that plays out onstage a dream, a supernatural visitation or something else? With its references to Aztec culture and scenes that take place inside the artists’ work, the opera and the set design leave that ambiguous.

Act 1’s cemetery is defined by the marigolds and candles that adorn the graves’ altars. The overall effect of set designer Jorge Ballina’s three-tiered structure is warm, romantic and traditionally Catholic. The flickering glow of Victor Zapatero’s soft lighting scheme amid the stone crosses could be at home in a score of older operas. But as the mechanics of the setting begin to move, the division of the world of the living above and the land of the dead below becomes more distinct. The tombstones and altars rise up, revealing an Aztec pyramid behind the flowers and candles, bringing the action into the underworld realm of Mictlán.

These two worlds are also are differentiated by color scheme.

“The blue is for the world of the living; it’s the color of the sky in the cemetery and also, Casa Azul,” Ballina said, referring to Rivera and Kahlo’s famous Mexico City residence, now a national museum and one of the settings in Act 2.

The set design avoids theater’s common use of printing technology “because it’s about painters,” Ballina said. “If (the set) had to be painted, it was really painted.”

The orange hues of Mictlán were informed by the glow of the candles in the cemetery and the marigolds, said costume designer Eloise Kazan. That extended to the inhabitants of the underworld, who appear in a range of orange period costumes depicting precolonial Indigenous people, Spanish conquistadors and Victorian figures.

While Rivera’s costumes primarily show him in the overalls he wore to paint, Kazan knew that dressing Kahlo would come with added pressure because of how carefully the artist crafted her own image.

“In a strange way, I felt a bit like a costume designer doing a piece about another costume designer because she was very much a storyteller with her clothes,” said Kazan. “It’s also very scary because of the weight of all her work and all the things that she means in Mexico.”

传统Tehuan•卡罗的复杂绣花a dress and shawl in Act 1 is also orange, but as she enters the world of Casa Azul and Rivera’s mural “Dream of a Sunday Afternoon in Alameda Central Park,” she cloaks herself in the blue of the living.

In perhaps the most visually stunning moment in the opera, Kahlo and Rivera are joined in Casa Azul by eight performers behind frames portraying Kahlo in the different guises she wore in her self-portraits. These include references to her works “The Wounded Deer,” depicting the artist as a stag pierced by arrows; “The Broken Column,” showing her spine crumbling like an architectural ruin; and “The Two Fridas,” which show personifications of the German-Jewish and Mexican halves of Kahlo sitting side-by-side, their hearts torn from their chests.

For Maza, images like this are meant for the heightened world of the opera.

“Opera is the greatest convention you can find onstage, it’s so metaphorical and symbolic,” said Maza. “It really gives you a chance to create your universe and gestures in abstract ways. It’s beautiful for stories that are very unreal in their reality.”

Reach Tony Bravo: tbravo@sfchronicle.com