At a world premiere of a new streaming series in Hollywood in February 2022, a castmember walked the carpet in front of TCL Chinese Theatre wearing a bold, asymmetrical top paired with black flare-leg trousers. After fielding a journalist’s compliment, the actress responded with a brief explainer of why she picked the understated yet chic look.

“I wanted to look good, but not too good, you know? I’m not the lead,” offered the veteran actress, who appears in a handful of episodes but not all of the season’s full order. “It’s never a good idea to outshine the stars of the show.” That didn’t happen on the night in question, as her famous co-star turned up in a showstopping gown.

The considerate castmember’s choice brought to light one of the lesser-known rules of red carpet fashion: Know your role and dress accordingly.

Over the past year, THR has been polling actors and fashion insiders about the politics of dressing that lie just below the surface at high-profile events, revealing a number of sartorial rules that are specific to red carpet culture.

“I have to deal with that a lot,” explains stylist Jason Bolden of making sure his clients are dressing the appropriate part. The A-list collaborator has a client list that includes Dwyane Wade, Michael B. Jordan, Yara Shahidi, Angelina Jolie, Cynthia Erivo, Trevor Noah and Serena Williams. “Sometimes I have clients who are just attending or presenting [at an awards show], and it’s about picking the appropriate dress or the appropriate suiting for that particular client for that particular event.”

In other words, if you’re simply a guest, save the yellow Valentino Couture for when you’re nominated and instead go with an all-black Saint Laurent look. “Showing up in a crazy gown as someone who is just a guest can look a little too try-hard,” hisses one stylist.

Actress Yvette Nicole Brown agrees. “Would you go to someone’s wedding and wear a white dress? No, you wouldn’t, especially if you’re a kind and considerate person. If it’s your premiere, you want to have your moment. But if you’re somebody who is on the list, be grateful that you made it there and that you get to have a Hollywood photo for the night, but it’s fine to let the stars shine.”

To illustrate, Brown recalls the 2017 Emmy Awards, when she attended as the plus-one of good friend Anika Noni Rose, who had been invited to be a presenter. “We were on the red carpet and her train was a little rumpled, so I got down to fix it. There’s a picture on Getty Images of me down on the floor fluffing her train because even though I was on the red carpet, it wasn’t my moment, it was my friend’s moment. I wanted her to be glorious on that night. You have to care more about other people and remember it’s not about you.”

How did that translate to what Brown wore? “You can pick a nice dress, but it doesn’t have to be the dress,” she says.

A more recent example of the rule: Megan Fox in a demure (for her) white Zuhair Murad gown to accompany first-time nominee Machine Gun Kelly at the Grammy Awards, where he donned a custom metallic Dolce & Gabbana silver-foil suit complete with a crystal harness. “Tonight was his night,” posted Fox’s stylist Maeve Reilly on Instagram, “so we really wanted to keep her look simple and classic so he could shine!”

There are other factors to consider. Bolden notes the thought that goes into what to wear to, say, a movie premiere where numerous members of a cast will be photographed together. Last year, he dressed client DeWanda Wise for the press tour for Jurassic World: Dominion, and the two “wanted to do a really big, explosive kind of gown, but you can’t do that when it’s a cast. You have to think about what the photo will look like. Instead, we went with these more statue-like, column-style dresses that played well along with everyone else. You have to be really thoughtful.”

But as with most fashion precepts — like wearing white after Labor Day — red carpet etiquette is, for some, a mere suggestion that can be easily ignored.

Gabrielle Union, who is styled by Thomas Christos Kikis, knows the rules but pays little attention. “No, baby,” she tells THR when asked if she dresses differently based on her role in any given event. “I am swinging for the fences every time I’m out there.”

Same for Daveed Diggs, who has turned up to events in eye-catching suits by Moschino and Atelier Versace: “There’s not a whole lot of strategy other than how do I feel when I hold the thing up? If it feels great when it goes on, that’s what I should wear.”

Tara Swennen, whose client list includes Kristen Stewart and Matthew McConaughey, says she thinks less about where her actors fall on the call sheet and more about the circumstances and ambiance of the event. “I try not to think about what their position is and more about where they’re going — the mood, the crowd, the vibe. I also just want them to feel comfortable.”

Insiders also are quick to mention that social media has made it easier to disregard fashion rules because when someone is posting a look on Instagram — a common practice and often done to help fulfill a contractual obligation with a specific brand as part of a larger deal — it’s generally not presented in the context of who else is on the red carpet.

THR also caught up with a pair of this year’s best supporting actress nominees for the upcoming Oscars and asked them if they are selecting more bold choices this season since they are in the mix. The Whale‘s Hong Chau says that while she’s still learning the ins and outs of the entire season, she mostly ignores the noise and focuses on “what’s going to make me feel good and comfortable.”

Everything Everywhere All at Once star Stephanie Hsu, who works with the styling team of Wayman Bannerman and Micah McDonald, says there’s always intention behind what they do: “Sometimes I approach it the same way I would for a role where if you go big one time, sometimes it’s nice to neutralize the palate and go clean the next time. Keep ’em guessing.”

And for Michelle Williams, the Oscar-nominated star of Steven Spielberg’s The Fabelmans who has long worked with stylist Kate Young, there’s only one rule that matters: “A good dress is a good dress is a good dress.”

This story first appeared in the Feb. 22 issue of The Hollywood Reporter magazine. Click here to subscribe.