On the third floor of The Ritz-Carlton Beach Residences on Lido Key, the door opens to Adrienne Vittadini’s exquisite smile.  Gracious and warm, she’s elegant in white (her signature). The décor is predominantly white, too (also her signature), and the effect is ethereal; in her new beachfront home you are suspended high in the sky with nothing to distract from Gulf of Mexico views that appear to stretch into infinity.

Born at the onset of the baby boom, the woman named in 1992 one of People magazine’s 50 Most Beautiful People in the World is magnificent still.  But Vittadini’s career has never depended on her stellar bone structure. Instead, the Coty Award-winning apparel designer and her husband, Gianluigi (Gigi) Vittadini, used their taste and talent to build a fashion empire. When the pair sold their company and the Adrienne Vittadini label in the late 1990s, they embarked on a new business venture called AV Casa, designing and building homes in luxury hotspots from Sarasota and East Hampton to Milan and Livigno, near St. Moritz.

Vittadini is known for blending formal European with casual contemporary furnishings. “I tend to mix periods, but I went more modern here than in most of my homes,” she says of the Ritz-Carlton beach apartment. Though the guest room reiterates her penchant for blue and white decorating, the rest of the residence combines black with white. Her trademark white-cotton, duck-upholstered pieces are contrasted with graphic black-and-white pillows and share the spotlight with black accent tables in hip new shapes.

But before the actual decorating began, the couple reconfigured the space. First, the dining room walls were removed to create one large great room. Supporting columns, originally thick and square, were trimmed into more diminutive Tuscan ones to afford a long vista from the entry through to the terrace and views of the water.

In the kitchen, wood-grained cabinets were painted to look as if they had always been the smoothest matte-lacquered white. “The kitchen was dark, and I am a fanatic about light,” Vittadini explains. “I also ripped out the island and drew [designs for] a new one that could be used for cooking.” The final change was the addition of mirrored backsplashes. “They’re great because I can see the reflection of the Gulf while I’m working in the kitchen,” she says.

Once the shell of the home was surgically corrected, the designer conceived couturier details. “We installed wall-to-wall sisal carpeting because I love to layer carpet on carpet,” she says. She added diaphanous linen gauze draperies to create depth, and layered on more textures with cashmere pillows and zebra-skin rugs. Vittadini chose a striped dhurrie carpet to optically widen the living room and tied white canvas cushions to chairs and benches as if she were lacing up St. Tropez espadrilles.

Vittadini peppered the all-white interiors of her new residence with the colorful and exotic spoils of the trips she and Gigi take in search of design inspiration and sources. In the red and white entry hall, for example, she displayed an Uzbekistani robe made from hand-dyed Ikat fabric, a hand-crafted rug and a natural woven basket from a favorite source, Alex Flamant in Belgium.

“I have a fetish for baskets,” Vittadini confides. Examples spring up everywhere: One conceals newspapers under an antique Chinese table from Hong Kong’s renowned Charlotte Horstmann; another, in the master suite dressing area, is tucked under a rustic French console. Indeed, Vittadini has lots of decorating fetishes. “I also collect boxes and pillows; there’s a story to every one of them,” she explains. Pillows found on trips to Morocco, Iran, India and more (“they come from everywhere”) are eye-popping accents to a white Ralph Lauren sectional in Gigi’s combination study/music room. The pillows pick up the red in an antique kilim carpet and in a series of abstract expressionist works by a close friend, the late Piero D’Orazio.

Although D’Orazio dedicated these “to Adrienne,” his art also hangs in galleries around the globe and in museums from the Tate in London to the Smithsonian. Discreetly tucked on a shelf in the music room is a reminder of another world-famous friend: a small photo of Adrienne cheek to cheek with Luciano Pavarotti, both of them beaming.

Outside this room, the Vittadinis’ four newest art acquisitions come into view, these by Irish artist Ronnie Hughes and purchased at Art Basel in Miami.

Although the fashion leader has spent a lifetime cultivating a trademark look, she proudly reveals that most of the home’s extraordinary wood pieces belonged to her late mother-in-law. “My apartment in New York is exploding with things that were in her home in Milan,” Vittadini says. For the Ritz-Carlton residence, she selected three matching armoires that fit perfectly into a dining room alcove. They appear to have been made for the designer’s new home, as do an exquisite round dining table, chandeliers in both breakfast and dining rooms, and a set of formal antique chairs. “Gigi’s mother covered the seats in silk; I dressed them down with canvas,” Vittadini explains.

The smile on her face indicates that these family pieces will be part of her life, even as color and design trends come and go. She will make them work because Adrienne Vittadini embodies the rarest of celebrity packages —an unaffected combination of style and substance.

Carol Tisch, founding editor of the national magazine Shelter, is style editor for Sarasota Magazine.