Paris - Paris fashion week got off to a charmingly chaotic start Tuesday with a rooftop catwalk show - the first by Franco-Cambodian designer Christine Phung - at which fashionistas played 'spot the model'.

Fashion watchers who trekked up the eight flights to the top of Paris's famed Galeries Lafayette department store were rewarded with clear views of the Eiffel Tower on a sunny September day.

But the models at Phung's catwalk debut were almost impossible to glimpse as they walked in a path hastily cleared among the milling crowd before being moved to an even less visible corner of the roof terrace.

"It was a lovely spot to hold a fashion show - and there was a great view of Paris - but unfortunately most people couldn't see anything (of the collection)," lifestyle blogger Marino Vizza told AFP.

Brought up in France by a Cambodian father and French mother, Phung's dual heritage is reflected in her use of printed silks.

Her spring/summer 2014 "Liquid Dilusion" collection featured a delicate palette of metallic grey, silver, white and ecru as well as black and ultramarine.

Looks inspired by "the possibilities of water" included billowing silk trousers teamed with a sheer halter neck top and pleated dresses and skirts.

Of around 10 looks in the collection, one was worn by a black model and two by Asian models.

The number of black models on the Paris catwalks can be expected to come under scrutiny this week following a blistering attack on the fashion world by models Naomi Campbell and Iman and model-turned-activist Bethann Hardison.

The trio earlier this month named a string of fashion houses who had used just "one or no models of colour" in recent collections and called for urgent action.

Elsewhere on Tuesday, Belgium's Anthony Vaccarello, known for his famously "slit-up-to-there" dresses looked to swim suits for inspiration.

Skirts and dresses in mostly black, white and red were strictly for those with legs worth baring.

"It just came out (like that) because the inspiration was the swim suit and I wanted the girls to move very fluently, very easily," he told AFP backstage after the show.

Oversized buttons created a military uniform look with skirts and dresses sporting triangular shapes at the front and cut-out strips at the side all worn with towering heels.

Other looks included tiny black shorts with a lace skirt covering just one leg.

Belgian Cedric Charlier, the former creative director of Cacharel, meanwhile, went for minimalist designs with a heavy emphasis on geometric shapes.

Black teamed with blue dominated the collection with other looks in metallic mint green, red and rust. Footwear was half sandal, half calf-high boot.

Tuesday is the first of nine days of women's ready-to-wear fashion that is due to wrap up on October 2. Among the shows scheduled for Wednesday are Dries Van Noten and Felipe Oliveira Baptista.

Highlights of the week are expected to be Hedi Slimane's Saint Laurent collection on Monday and New York fashion star Alexander Wang's second show for Balenciaga on Thursday.