Low-rise jeans, checkered Vans, and that iconic leather necklace: How 'The O.C.' costume designer accidentally became a '00s trendsetter

Insider caught up with Alexandra Welker, the costume designer whose favorite cultural touchpoints from the 1980s blended with early aughts' surf brands to create the styles seen in season one of "The O.C."

Welker was born and raised on the east coast, so the twist on teenage fashion that we saw in the series was a filtration of Welker's personal taste combined with the styles you would have expected to see on everyday rich kids living in the eponymous Orange County.

Prior to the first season of "The O.C," Welker had been primarily working on feature films. She was the costume designer for 2001's "American Pie 2," which takes place primarily at Lake Michigan. This provided ample opportunity for Welker to explore beachside trends of the day.

"I had friends in Costa Mesa, a Southern California surf town, and I became friends with the guys that owned Paul Frank," Welker told Insider over a Zoom call. "And they in turn knew all the other clothing people because they all surf together and they'd all grown up together."

"My friends introduced me to the guys at Stussy and the guys at Hurley and the kids who ran Billabong," she continued. "I used a lot of their stuff in ['American Pie 2'] because it made it very fresh and timely. So then for 'The O.C.,' I actually kept a lot of those relationships going."

Welker walked us through the costume designs of the pilot episode, highlighting references you might not have noticed (like a pair of checkerboard Vans paying homage to "Fast Times at Ridgemont High"), explaining her trendsetting approach to "high-low" outfit pairings, and reflecting on the cyclical nature of fashion.

Each of the main characters has a distinct sense of style. Ryan is practical and brooding. Seth is ironically detached and lonely. Marissa is preppy and "troubled." Summer is bubbly and sharp.

Welker, a character-driven creator, helped establish their stories through the clothes they wore from the jump.

"Costume design is just visual shorthand for who we are and where we're from and what we're going through in our lives," Welker said. "It's our hopes and dreams and aspirations and all that other stuff we don't necessarily realize we're telegraphing."

Ryan (played by Ben McKenzie) comes in hot with a signature outfit: White v-neck T-shirt, gray hoodie, black leather jacket, and a single strand of rawhide leather tied around his neck.

"Ryan totally dressed like the bad boy I had a crush on in high school," Welker said with a laugh.

Welker wanted his clothing to seem a bit more classic, reflected by what would be accessible to him at his "economic status - or lack thereof." Welker believed Ryan would use his clothing as an "armor," an image of toughness he was projecting.

"And then everybody always asks about the necklace," Welker said. "I had done a lot of work with different rock and roll bands on occasion, and one of the things I used to do pretty routinely would be to make somebody a bracelet out of a piece of rawhide. You know, soften it up and tie it on a few times. It's a great effortless-but-cool accessory. For some reason with Ben I just was like, 'Try it as a necklace instead.'"

Seth (played by Adam Brody), in contrast, is a prototype hipster who's always sporting graphic T-shirts blended with the aesthetic of a Florida retiree. His style stood out among the crowd of early 2000s teen boys because it tended to be more tight-fitting.

"One of the things that's really funny now to me now is how we're moving back into early aughts fashion - all the high school kids in my neighborhood are wearing super giant baggy clothing," Welker said. "At the time that we were making this show, we were coming out of the '90s and you'd wear your t-shirts three sizes too large and big saggy pants."

Welker saw how the on-trend style for boys was all oversized, so she reached back in time a bit to help create Seth's looks.

"I remember especially looking pictures of like 'Dogtown and Z-boys' skaters from Southern California," Welker said. "The '70s was all about that skinny silhouette. I can remember being a kid in the '70s and boys all liked skinny corduroys and tight-fitting T-shirts and so forth."

Welker tailored all of Seth's clothes, and even some of Ryan's, to "fit as slim as possible." But the extras on set and side-character frat bros of "The O.C." were left to their oversized devices.

"The boys in the background are still in that baggy silhouette. But these were our two heroes, so we wanted them to look cooler," Welker said.

"She seems very much like the epitome of this community, at least through Ryan's eyes," Welker said. "But then you come to realize that she's actually an individual who isn't in lock-step with what her mom wants or what her boyfriend wants or what her best friend says she should be doing."

Welker continued: "She's looking for ways to break out of that, and so I was trying to subtly signal that in some of her clothing choices."

The first time we see Marissa, she's wearing an asymmetrical top with low-rise jeans (another staple of the early '00s) and pointed flats.

As a cultural product of the '80s, Welker has always personally loved a pointed flat. It was a bonus that they helped keep Barton closer to the same height as her costars like Rachel Bilson (who played Summer).

Welker found many of the clothes Marissa wore (like the shirt seen in the above photo) at sample sales for local designers in Southern California. It was part of Welker's experimental costuming, which she calls "high-low" shopping.

"It's so funny now to look back on that, but at the time if you were wearing something that was a designer outfit or a high-end label outfit like Juicy, it would be a head-to-toe type thing," Welker said. "But the way I approached it [...] was this idea of mixing and matching. So you might be wearing a Rachel Comey dress, but then you'd have your Old Navy flip flops and a cute straw bag that you bought at the vintage store."

"It all seems normal now, but at the time that was pretty revolutionary," she added.

"The O.C." was a total unknown when Welker was helping put the pilot episode together. Series creator Josh Schwartz was just 26 years old - he remains the youngest network TV showrunner of all time - and the cast, aside from Peter Gallagher, was not comprised of major household names. That meant Welker was getting turned down by major brands when she asked for pieces that could be placed in the series.

In the pilot episode, Marissa helms a fashion show to help raise money for charity. The characters and background actors name-drop designers like Vera Wang, Betsey Johnson, and Prada in reference to their dresses and accessories. But Welker had a hard time actually getting major designers to place their pieces in the episode.

"I was calling around and everybody turned me down," Welker said. "They were just basically like, 'Hey, great, we'd love to help you, but it's a TV pilot. We can't do anything.'"

But it only took a few episodes for the buzz to really start around "The O.C.," and midway through the first season, Fox had already extended their run of episodes. Welker remembers how the young stars started excitedly telling stories about getting recognized at a restaurant, a telltale sign of fame.

Then, Welker was suddenly getting calls from brands eager to be a part of the wave.

"I had companies just throwing things at me," Welker said. "They were like, 'Please, please use our stuff.' And I was quietly chuckling to myself because several of them were companies that I had approached with the fashion show."

"It's very understandable that they wouldn't want to go with a complete unknown," she added. "And it also makes sense that they would want to be attached to something that setting fashion trends. What a difference 10 months makes."

Besides the calls coming in from designers, Welker also suddenly found herself fielding calls from fashion reporters who wanted to know what it was like to be a trendsetter.

Welker says the first time this happened she muted her phone and turned to her team in disbelief.

"And they were like, 'Oh well the Uggs, the miniskirts, the high-low shopping, the mismatched colors,'" Welker said. "And I was like, 'I'm doing all of that just because I think it's interesting.' When you're in it and you're telling a story, it's not necessarily thinking about it objectively from a fashion standpoint."

Fans of "The O.C." know how Summer's introductory scenes establish her as shallow, mean, and rather unsupportive of her friends. But by the end of even the first season of "The O.C.," that version of Summer has evolved into a more witty and caring character.

You get a sense of Summer's beginning point in scenes like the pilot episode's beach party. Most of the background extras wore very similar outfits comprised of staple tops and plain skirts or pants.

"They're on-trend rather than actually setting a trend or exploring something outside," Welker said. "Whereas Marissa - consciously or not - is always starting to make the interesting choices. And that's also part of the Summer-Marissa dynamic. At the beginning of the show, Summer was much more on trend and in the moment."

But as the season (and series) progressed, Summer began coming into her own more and "making more interesting fashion choices," Welker said.

Then a pair was featured in the 1982 movie "Fast Times at Ridgemont High," a coming-of-age story about Southern Californian high schoolers.

A memorable scene included Sean Penn's character, Jeff Spicoli, pulling a pair of the black-and-white shoes out of their box and whacking himself on the head to prove how stoned he was.

"I'm old enough that 'Fast Times at Ridgemont High' was one of my touchstones," Welker said. "I knew the Vans guys because of my friends [at Paul Frank], and when I found the checkerboard Vans, I was just like, 'Oh my God, I love these things,' and I put them on Marissa. I was really super happy when they resonated."

"For a certain segment of the population they've never gotten out of style," Welker said. "But for the general public they kind of go in and out of style."

So as normal as it looks now to see a Chanel bag-loving teen to throw on a pair of skater shoes (Welker says it seems like "every third person on the street is wearing Vans"), back in 2003, this was an unexpected fashion choice for Marissa.

"Fashion is always in a 20-year cycle," Welker said. "I remember in the '90s that '70s vintage was huge. And then I feel like over the past decade we were exploring '80s-informed stuff. And then of course we've been mining the '90s for the last 10 years or whatever. So now the early 2000s are having their fashion moment again."

"I'm super hopeful that ridiculously low-rise pants don't come back," Welker said. "Like Frankie B's with their two and a half inch long zippers. Even on the fashion model, 'perfect body' person - they're still not very flattering, but they were a huge thing for awhile. We certainly did a lot of very low-rise pants."

Welker finished out the first season of "The O.C.," but then returned to working on feature films.

"I was like, 'This is amazing but I'm fried,'" Welker said. "Eleven and a half months of 14-hour days - it'll catch up with you."

Those years still hold a special place for her in the same way they do for the millions of fans who tuned in.

"We really created some indelible characters that still resonate," Welker said. "People either saw themselves in these characters, or saw people that they wish they knew or wanted to be."