(InStyle.com) -- Toss that basic black and indulge in a fashion fantasy this year. We asked the four gorgeous stars of ABC's new TV show "Cashmere Mafia" to take part in a little experiment: If you could slip into a different guise for a day, what would it be?



Frances O'Connor in Zac Posen silk gown, José and María Barrera rhodium-plated earrings with Austrian crystals.



Frances O'Connor glams it up



Understated when it comes to her own style and buttoned up in banker stripes as Zoe on Cashmere Mafia, Frances O'Connor, 40, has been hankering for an infusion of pure glamour.



"I love the idea of wearing a dress that's a work of art in itself," says the actress, who slipped easily into a red-carpet fantasy with a mouthwatering cherry-hued gown by Zac Posen.



O'Connor's "safety first" approach to fashion means living mostly in simple Marc Jacobs pieces, but it's a sensibility that doesn't offer much in the way of frippery -- which suits her just fine. "I don't like to stand out too much," says the willowy Anglo-Aussie beauty.



Still, Posen's fluttering cascades of silk offer both a role reversal and a respite. "A fantasy has to move you to feel like a different person," she says. "That's fun for a day. Then I like to put my jeans back on and go home."



Lucy Liu relives the forties



Few decades enthrall Lucy Liu like the 1940s. "I like the idea of updating a traditional silhouette from that era in a fresh way," says Liu, whose character, Mia, reigns over a New York publishing fiefdom in power looks by Dolce & Gabbana, Valentino and Rachel Roy.



Despite its abstract floral print, the ruffled organza dress by Christian Lacroix would seem right at home on the cover of a World War II-period glossy, yet Liu imbues it with a distinctly modern verve. "There was something really elegant and erotic about women back then, with their girdles and cinched-in waists," she says.



On the set the 39-year-old star relishes watching costume designer Patricia Field work her sartorial sorcery with a swirl of offbeat textures and trimmings. "The other day my character was wearing a gold lamé striped dress with a coffee-hued belt, black leggings and green earrings. It's contagious," says Liu, who finds herself mixing -- and not matching -- more freely these days.



Miranda Otto indulges in gems



Famous for playing a Middle Earth maiden in the Lord of the Rings movies, Aussie actress Miranda Otto found herself dressing a little like one offscreen too, in muted, ethereal garb. But her arctic complexion and fiery tresses are the perfect canvas on which to throw splashes of drama.



"Shooting Cashmere Mafia [the 40-year-old beauty plays steely hotelier Juliet] has made me lust for accessories," she says. Presto: Otto is resplendent in scads of jewelry. "Wearing stacks of the stuff makes it more interesting," she adds.



There's just one catch to donning such beguiling accents: "My 2-year-old daughter, Darcey, wants everything."



Bonnie Somerville goes for fifties bombshell



Bonnie Somerville longs for the bygone days when women were perennially polished.



"In the fifties you'd never leave the house without your hair done, your face on, and a nice dress. Me, I have my staple uniform of jeans, tank tops and flats."



To resolve her clothing ennui, the actress chose a dazzling yellow Lela Rose number that is equal parts Bond Girl and Palm Beach socialite. "It's something I never thought I could wear for daytime," says the Brooklyn, New York-bred singer and actress who plays Cashmere's trendy cosmetics exec, Caitlin. A skinny metallic belt gives the look more of a now vibe.



"On the show, with everything we wear, Patricia Field says, 'Put a belt on it!'" says Somerville, 33. "Now I'm buying belts
Who has their own style? What did Bonnie Somerville wear? Who wears scads of jewelry? Who  has their own style? Who is wearing belts on and off screen? What did Miranda Otto wear? Who likes 1940's silhouettes?
Frances O'Connor a dazzling yellow Lela Rose number Otto Frances O'Connor, Somerville, muted, ethereal garb. Lucy Liu
question: Who has their own style?, answer: Frances O'Connor | question: What did Bonnie Somerville wear?, answer: a dazzling yellow Lela Rose number | question: Who wears scads of jewelry?, answer: Otto | question: Who  has their own style?, answer: Frances O'Connor, | question: Who is wearing belts on and off screen?, answer: Somerville, | question: What did Miranda Otto wear?, answer: muted, ethereal garb. | question: Who likes 1940's silhouettes?, answer: Lucy Liu