PARIS (Reuters) - Leave it to Alber Elbaz, creative director of Lanvin, to pull off a Paris Fashion Week show on Thursday that retained all its elegance and class even with Kim Kardashian and Kanye West in the front row.

Popcorn and champagne distracted the audience for a time before the reason for show's delayed start became apparent: the ubiquitous Hollywood couple swooped in 40 minutes late, eliciting boos from the standing photographers.

But after their tardy entrance, the focus went right back on Elbaz's elegant creations.

Held under the impressive glass ceiling of the prestigious National Fine Arts School on the Left Bank - which for centuries has trained France's great painters and sculptors - the Lanvin Summer 2015 collection was a study in monochromatic chic.

No need for grand gestures here as seen in other shows this fashion week - whether the letters of Anthony Vaccarello's name that showed up in his clothes on day one, or the space alien meets cotton candy vibe of Manish Arora's collection earlier on Thursday.

Elbaz's long, sinewy clothing, from the fabulous billowy black silk jumpsuit to the oversized blue blazer, brought refreshing neutrals to the forefront, in nudes, blacks, ivories, amethysts and coppers.

Dresses of silk charmeuse, in all that fabric's ethereal polish, took centre stage, with the fluid material merely skirting, never hugging the body.

A flapper-length dress in flesh tones found its modernity in gold hardware at each side that attached both front and back.

Lanvin's study in monochromatic chic was broken by a foray into prints, but when they came their deconstructed floral, garnished with glimmery shine, were welcome.

Elbaz took up the yellow and blue so beloved of the fashion set this season, but his offerings were the antithesis of the overblown patterns seen this week at Carven and Guy Laroche.

Oriental swirls of yellow-gold and navy bedecked dresses, skirts and jackets, while an exquisitely tailored, sensible blue jacket was paired with hip-hugging gold and blue pants worthy of a bullfighter out on the town.

The final look of show was a resplendent silk dress with flowing sleeves cut to mid-thigh in tones of mustard and slate that projected an airiness and effortlessness.

The stout, bespectacled Elbaz gave a demure little bow after the show, with an endearing self-deprecating gesture at his own modest all-black outfit accessorized by well-worn brown boots.

And the circus started up again, with Kanye and Kardasian being whisked off backstage amid a crush of TV cameras, leaving the catwalk littered with popcorn and champagne glasses.