CNN  — 

Clothes aren’t just items to keep you warm or cool – they also indicate status, showcase defiance, and even alleviate anxieties.

For tennis legend Billie Jean King, clothes allow female tennis players to express their individuality through colors and prints – a right she and the embryonic Women’s Tennis Association (WTA) fought for in the 1970s when white was ubiquitous as the sport’s color.

Wimbledon still employs this rigid all-white dress code – first implemented to camouflage sweat stains. These days it also helps the SW19 grand slam retain a sense of uniqueness in relation to the Australian Open, the French Open and the US Open, but arguably it also curtails players’ individuality.

More pressingly, for players menstruating it creates anxieties as to whether blood is visible on white clothes.

“My generation, we always worried because we wore all white all the time,” King tells CNN’s Amanda Davies. “And it’s what you wear underneath that’s important for your menstrual period.

“And we’re always checking whether we’re showing. You get tense about it because the first thing we are is entertainers and you want whatever you wear to look immaculate, look great. We’re entertainers. We’re bringing it to the people.”

Following the publication of King’s comments, reports in the British media appeared, suggesting that Wimbledon would relax its all-white underwear rules for female tennis players.

In response to the reports, the All-England Tennis Club (AELTC) released a statement to CNN on Tuesday saying: “Prioritising women’s health and supporting players based on their individual needs is very important to us, and we are in discussions with the WTA, with manufacturers and with the medical teams about the ways in which we can do that.”

Tournament organizers had been under pressure to relax its strict dress code since Wimbledon this year when campaigners gathered at SW19 with signs that read “About bloody time,” and “Address the dress code.

Billie Jean King won Wimbledon six times.

It followed the comments made by several women including former Olympic champion Monica Puig and Australian tennis player Daria Saville who spoke about the “mental stress” caused by the all-white dress code and “skipping periods” as a result.

Manufacturers are beginning to develop solutions, even as Wimbledon’s dress code remains, with Adidas telling BBC Sport that it had period-proofed its women’s training products.

“You feel like you can breathe and not have to check on everything every minute when you sit down and change sides,” King adds, referring to wearing dark clothes underneath.

“So at least it’s been brought to the forefront, which I think is important to have discussion.”

As well as the all-white policy creating anxieties for players on their period, King points out that it can be difficult for fans trying to distinguish between players on the court.

“Nothing is worse in sports than when you turn on the television and two players are wearing the same uniform or same outfits. It’s horrible. No one knows who’s who.

“This is one of my pet peeves, I’ve been yelling for years. Have you ever seen any sport where the people wear the same outfit on each side?”

Billie Jean King defeating Bobby Riggs in the Battle of the Sexes marked a historic moment for women's tennis, and sport.

‘Billie Blue’

The fading taboo surrounding menstruation is evidence of the progress made by women’s sport in recent years, a fight which King has led for 50 years.

Two years ago, the Federation Cup – women’s tennis’ flagship international competition in which players compete as part of their national teams – changed its name to the Billie Jean Cup King to honor her, and now the tennis great is using clothes to highlight the champions of this year’s event with a ‘winner’s jacket’ designed by renowned fashion designer Tory Burch.

Drawing from the tradition of the famous ‘Green Jacket’ donned by the winner of The Masters golf tournament every year, Burch designed a blue jacket for the winners of the Billie Jean King Cup in the hope that it will eventually become as iconic as its predecessor.

Every stitch, every seam, and every inch of fabric is steeped in symbolism.

Its color, “Billie Blue” was chosen “because many times through her amazing career, King has worn blue,” Burch explains.

Most famously, King walked onto court to play Bobby Riggs in the 1973 “Battle of the Sexes” wearing a blue and menthol green dress, buttoned down the front and adorned with rhinestone detailing.

Her shoes were also blue, deliberately chosen to match her dress, stand out on the still novel color television and subvert gender stereotypes.

“The shoes and the color, everything is very important to me,” King says. “I always try to have meaning in what I wear.”

Since that seminal moment when King defeated Riggs 6-4 6-3 6-3 in front of an estimated worldwide television audience of 90 million, gender equality inside and outside sport has progressed, though sometimes haltingly, stumbling backwards or sideways a few steps.

That same year, the US Open became the first of the grand slams to offer equal prize money to men and women, while the US Supreme Court granted women the right to an abortion in Roe vs. Wade, though this decision was overruled in June.

“Every generation, they go farther and farther away from the beginnings of the fight,” King says. “I think history is so important because the more you know about history the more you know about yourself.”

King hopes that the current generation of female tennis stars, those who will wear her specially designed jacket as the winners of the Billie Jean King Cup, will pick up the baton.

“But the most important thing from [history] is it helps you shape the future and that’s what I want these young women to do. It’s their job now to step up, lead and shape the future.”

Billie Jean King worked with fashion designer Tory Burch on the Billie Jean King Cup's 'winner's jacket.'

And inside the jacket, to remind the champions of the Billie Jean King Cup of the ‘fight’ and their place in it, is a message from King herself.

“Congratulations on winning the 2022 Billie Jean King Cup,” King reads aloud. “As a member of the first winning team at the Federation Cup in 1963, I dreamed to share this title with women like you.

“Tory Burch shares my passion for tennis and women’s empowerment. We designed the champion’s Billie Blue Jacket to symbolize your incredible win and how far women have come in sports. Together, we can make equality a reality. Billie Jean King, be bold.”