Nearly 28 years since “Clueless” premiered in 1995, colorful plaid sets still evoke the teenage spirit of Cher Horowitz, Alicia Silverstone’s character, in all her delightfully oblivious, fashion-obsessed, Beverly Hills glory.

The film’s greatest legacy is its vibrant fashion, courtesy of Mona May, the film’s costume designer, and Amy Heckerling, the director. When a celebrity wears a plaid outfit, Cher’s is often the first name to come to mind. Olivia Rodrigo, Harry Styles, Beyoncé — the list of famous Cher interpreters goes on.

Ms. Silverstone herself has sported similar yellow plaid looks in social media videos recreating scenes from the film, and in a 2019 performance on “Lip Sync Battle.” Essentially, if it’s possible to own a pattern, “Clueless” forever owns yellow plaid.

Now, the actress has revived her role in “Clueless” and her iconic yellow plaid suit for a Super Bowl commercial for Rakuten, a shopping platform. In the ad, Ms. Silverstone recreates classic scenes from the film and extols Rakuten’s cash-back offerings. The ad campaign enlisted one of Ms. Silverstone’s real-life friends from the fashion world: Christian Siriano, the designer.

Mr. Siriano designed an updated yellow plaid look that Ms. Silverstone wears in the commercial, as well as three “Clueless”-inspired looks for his upcoming runway show.

“Any young fashion designer watching ‘Clueless,’ you kind of fall in love with the fashion,” Mr. Siriano said. “Now, Alicia is one of my best friends.”

About seven years ago, Mr. Siriano invited Ms. Silverstone to one of his fashion shows. “I had never been to a fashion show in New York in my whole life,” Ms. Silverstone said. But Mr. Siriano’s invitation intrigued her, because he said he donated to animal charities and avoided using wool, leather or fur.

“I was incredibly impressed,” Ms. Silverstone said of the show, “and continue to be impressed and inspired by him all the time.” Now, Mr. Siriano frequently dresses Ms. Silverstone, and the two have even recreated scenes from “Clueless” together. He makes a cameo in the Rakuten commercial, as one of the students in Cher’s debate class.

Mr. Siriano said that the yellow plaid has resonated for so many years because it’s a “bold, graphic, abstract print.” The outfit was a “take on the schoolgirl uniform,” he added, made playful with Mary Jane heels, over-the-knee stockings and an eye-popping, sunshine color.

“Seeing this young girl in what is a historically classic fabrication but in a young, youthful, playful, cool way was very new,” Mr. Siriano said. At the time of the film’s release, grunge fashion dominated the real world, and the high-fashion, European-inspired, polished and well-tailored looks of the “Clueless” characters were a departure from the typical teenage wardrobe.

Perhaps that deviation offers another reason that generations continue to find inspiration in the fashion of “Clueless.” It’s a way to take a stroll through its glossy, bubble gum world, even if it was mostly movie magic. Today, Cher is a popular Halloween costume and source of style inspiration. The #cluelessoutfits tag has more than 24 million views on TikTok, with a slew of videos of people in the film’s quintessential looks, like Cher’s Dolce & Gabbana plaid power suit and Calvin Klein slip dress.

Updating the plaid suit for the Super Bowl commercial took a careful eye. Mr. Siriano modernized it with a different plaid pattern, a cropped jacket, no cardigan, black shoes, and a more adult version of a pleated miniskirt, he said.

“I think we were really riding a fine line,” Ms. Silverstone said. “Because everyone wants it to be this elevated, sophisticated, adult version — but then also, everyone’s totally obsessed with it staying the same.”