After 20 years in service, the Paris concept store Colette is due to close its doors on Wednesday20 December, marking the end of an era in which it radically revamped the face of French art de vivre, made streetwear high fashion, and redefined what shops could be.

Situated on the Rue Saint-Honoré, it was opened in 1997 by Colette Rousseaux and her daughter, Sarah Andelman. Back then, it faced a city that was, according to Andelman, “totally dead. Today it feels totally natural to mix fashion, food, lifestyle.”

When the store opened, it made a startling impact, with a style in direct contrast to the country’s fashion history and its couture houses. But this, say fans, was precisely its draw. The Chanel designer Karl Lagerfeld said last year that it was the only shop he frequented, “because they have things no one else has”.

Pharrell Williams at a Chanel x Colette event last month. Photograph: Maitre/WWD/REX/Shutterstock

The week before it closes is quite a scene. The usual clientele – hip young things, looking to stock up on rare Balenciaga merchandise – have been replaced by a clientele broader than ever before. The shop assistants tell me it feels like a “tourist attraction”. There isn’t room to move beside the coffee-table books, and the sense of urgency is palpable. Most popular are items with the famed Colette blue dots logo — T-shirts, baseball caps, key rings, lighters. They are all “flying off the shelves”, the staff explain. No doubt these items will reappear online at outrageous prices soon after, all to be collectors’ items.

“I can’t believe it is closing – Colette felt so ingrained in the Parisian landscape. It had brought a sense of the avant-garde that the local fashion scene had never seen before, and which no other boutique can offer in the same way to this day,” said Mélody Thomas, a Paris-based journalist who writes for the likes of fashion magazines L’Officiel and Jalouse, and went to the store a few days ago looking for Glossier beauty products, which Colette stocks exclusively.

David and Victoria Beckham at the store in 2006. Other famous fans include Karl Lagerfeld and Pharrell Williams. Photograph: Marc Piasecki/FilmMagic

“I had never seen the place as full, you could barely move. People who might not even have been aware of it suddenly wanted to catch a glimpse of it before it closed,” she added. One of the things she would miss the most is the global magazine section, a point of reference for journalists.

Colette’s success has, in part, been about its evolving approach to fashion. Using a stream of collaborations and launches – the shop windows became tantamount to a shrine, usually changing on a Sunday – it is thought the windows have hosted more than 2,000 displays. It also defined what a concept store was, setting the tone for shops like Dover Street Market in London.

“Rather than a static boutique, the place was thought of like a style magazine: the windows that changed regularly were like the cover, the ground floor filled with accessories like the opening pages, the top floor with fashion, the bottom with food: the idea was a place of life rather than a place of luxe,” said Guillaume Salmon, Colette’s head of communications, who has been working at the company for 18 years. “The idea was to have a wide enough offer to allow a diverse crowd to mix harmoniously.”

Colette Roussaux and Karl Lagerfeld last month. Photograph: Maitre/WWD/REX/Shutterstock

In terms of style, not only did it epitomise the idea of streetwear as high fashion, but it also crystallised the idea of “one-offs” – exclusive, but not necessarily unaffordable, pieces. Fashion as collectors’ items. There was the launch of musician Pharrell Williams’s exhibition collaborations (ranging from a team-up with Comme des Garçons and Colette for a perfume to, more recently, sneakers jointly produced with Adidas, Chanel and Colette). Other events have included a public funfair at the Tuileries for the store’s 15th anniversary, a book signing by famed Vogue editor Grace Coddington, and an exhibition by stylist Giovanna Battaglia.

“It brought in the idea of then rare collaborations, and the idea of single, unique, temporary products that could only be found here, all packed with an overall sense of rush, excitement and ongoing cultural events,” said British-born, Paris-based stylist Natalie Yuksel, who started working at the store aged 18 as an intern, and spent “yonks” at every single one of the events Colette would throw.

More significantly, Colette delivered a message of cultural diversity: when Paris rapper Booba offered private showcases, he insisted on Colette; the entire shop was dedicated to Paris Saint-Germain FC and its former star striker, Zlatan Ibrahimović, when he launched his perfume. All of this projected sporty, non-elitist expressions of Frenchness into an avant-garde sphere that became the store’s greatest asset. “This hybridity is perhaps what I’m proudest of,” said Salmon. “Something a bit more democratic, that stretched the image people might have of France.”