Guy Laroche designer Marcel Marongiu introduced a "no-nonsense" collection featuring streamlined graphic shapes, plunging necklines and experimental materials at the Paris shows.
On day two of Paris fashion week, Marongiu teamed light silk overalls with bikini tops and tuxedos with shorts for a "light, effortless" silhouette.
Experimental materials included luminous acrylic glass on strappy bain de soleil dresses and light scratched leather that gave a rough sheen to bags, shoes and details on coats.
Marongiu, artistic director at Guy Laroche since 2007, is one of a raft of designers such as Hedi Slimane at Yves Saint Laurent and Alexander Wang at Balenciaga currently working to reinvent fabled fashion names for the modern market.
Prior to his appointment the house had seen a revolving door of designers attempt to breathe new life into it including Alber Elbaz, now at Lanvin, and Herve Leroux, founder of the Herve Leger label.
The French-Swedish designer, who in the past has looked to David Bowie for inspiration, said the idea for his latest collection came from someone even closer to his heart than Bowie.
"The starting point of this is actually a picture of my mother," he told AFP ahead of the show.
"My mother had a very interesting sense of style. She mixed freely, she was (a) very independent, intellectual woman.
"She could one day have cropped jeans with my father's pea coat and the next day an embroidered little dress with a really tight waist. She played with everything. She was far from a fashion victim," he said.
Marongiu's summer 2015 collection, which came in a palette of butter yellow, eggshell, claret red, and navy, also featured dresses with laser-cut designs and tri-colour leather panels.
As well as his mother, Marongiu said he was inspired by the US designer Claire McCardell (1905-1958) who was renowned for her stylish yet affordable women's sportswear.
Marongiu's objective this season was to be both stylish and simple to wear.
"The collection opts for... an overall no-nonsense approach," the house said in a statement.
Label founder Guy Laroche, who died in 1989, was known for clothes which were both wearable and high fashion. Signature looks included plunging neck and back lines.
"I don't like throwing away fashion. I don't like fast fashion," Marongiu added.
"The work I've been doing for Guy Laroche is not much about fashion, it's about style... (it's) not about a dated garment for one season," he said.
Nine days of Paris ready-to-wear shows for spring/summer 2015 run until Wednesday.
The highlight of the collections is Saturday's show by Jean Paul Gaultier, the flamboyant French designer's last ready-to-wear show before he stops to concentrate on couture.