When Sir Elton John takes the stage, his music isn’t the only thing that’s loud.

The pop superstar’s outlandish outfits are almost as enduring as his amazing melodies, so in a new movie about his life, it’s crucial that his Technicolor threads pop off the silver screen.

As “Rocketman” hit theaters on Friday, it was up to Taron Egerton to hit all the right notes as the singer and costume designer Julian Day to make sure he looks smashing – and authentic – while doing it.

“All costumes are significant, but I think they’re very significant in telling the story of his life,” Day told the New York Daily News. “Obviously we’ve got his stage-wear and his exaggerated lifestyle. All of that comes into play.

“There’s just a connection with some of the songs and the outfits. Like ‘Goodbye Yellow Brick Road,’ it’s all about the idea of ‘Wizard of Oz,’ the ruby red slippers, the Lion’s coat, the Tin Man’s shirt, the Scarecrow hat. … I just tried to put other references into the film.”

“Rocketman,” directed by Dexter Fletcher, follows John’s meteoric rise to global fame, and his personal struggles along the way.

The movie isn’t a straight-up biopic, but rather a fantastical musical that weaves John’s many hits into a larger story covering his stardom, substance abuse and sexuality in a time when being gay could have torpedoed his career.

“Elton really encouraged Dexter and Taron to go for the stuff that was real but not flattering, and very vulnerable and very personal,” Bryce Dallas Howard, who stars as John’s mother, Sheila Eileen, said.

“He’s connected to this part of himself that is raw and truthful and wild and brave. Because he’s someone who is so inspiring, it is absolutely important to get an audience to experience as close a journey to what Elton experienced himself. His sexuality is a huge part of his identity. … He had relationships that were really defining in his life, and showing and revealing the nature of those relationships is a huge facet of this story.”

To fully commit, Egerton, 29, sang classic John hits including “Tiny Dancer,” “Bennie and the Jets” and “Crocodile Rock” that are featured in the film.

John, who is also executive producer, stopped by the set one day to meet the heads of every department, Day said.

“I showed him all the concept drawings I was doing for his looks, and he approved them all,” Day said. “It was great. It was very good to have him down there and just sort of get some feedback from him, and just see that he liked them. That was my mission, to make sure Elton liked everything he saw in the film.”

The relationship between John and his longtime songwriting partner Bernie Taupin – who is played by Jamie Bell – is also explored the movie.

Howard, 38, was with Taupin this month at the Cannes Film Festival in France, where “Rocketman” got a standing ovation.

“I said to Bernie, ‘Is this surreal? And he was, like, ‘Yeah.’ … Then he paused and he goes, ‘You know, we’re not dead yet.’ It was this really funny thing of, these kinds of celebrations often happen after the fact,” Howard said. “For them to be alive and well and to be able to participate it, and to guarantee the authenticity of it, that’s very unique, and really special and really fun. So of course, seeing their reactions after seeing the film and stuff, it’s really amazing.”