Cool and Sexy: By day, sneak a glittery tank (Tucker, $428; TuckerWebShop.com ) under a cardigan (Vince, $275, Saks Fifth Avenue; 877-612-7257). Drop the sweater for evening, letting color—orange trousers ($138; JCrew.com ) and gilded flats (Kate Spade New York, $225; KateSpade.com )—take over. Necklace, Sheila Fajl, $90; HSN.com . Clutch, JCPenney, $30; 877-346-3527 for stores.

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