The Hottest Trends of 2011

This year, stars mixed bold, expressive colors-and if they clashed, so much the better! Sarah Jessica Parker chose a Prabal Gurung ensemble in red and hot pink, while Emma Stone tried out the same color combo in an outfit from Giambattista Valli. Zoe Saldana skipped the separates in favor of a fringed Lanvin minidress in a rainbow of hues.

What's more fitting than stars wearing stars? Solar system-inspired selections from Dolce amp Gabbana's Fall 2012 collection made their way into the wardrobe of everyone from Olivia Wilde to Kim Kardashian to Penelope Cruz.

Blondes don't always have more fun. Drew Barrymore, Scarlett Johansson, and Blake Lively all traded their golden strands for fiery copper hues this year.

In 2011, denim was not synonymous with indigo-celebrities chose from a variety of bright jeans. Malin Akerman opted for cobalt skinnies, while Kerry Washington played up her legs a cherry red pair from Express. And the always fashion-forward Rachel Bilson brightened up a neutral look with violet AG jeans.

Celebrities certainly weren't shy to try out statement-making nail shades-the brighter, the better! Hailee Steinfeld accented her grey ensemble with a pewter mani, Katy Perry dressed up her coral talons with neon nail art and 3D flowers, and Heidi Klum's cerulean nails were a perfect match to her printed frock.

It took a princess to bring back pantyhose! Rumored to be a royal requirement (no bare legs in Buckingham Palace), Catherine Middleton appears in public wearing sheer stockings, with sister Pippa following suit. Not only do the stockings have a slight sheen, they also give legs an instant glow.

The '90s were defined by the Rachel cut, but in 2011, it was all about the bob! Celebrities were replacing their longer styles for angled bobs, proving the style works on almost everyone. Dianna Agron, Jennifer Aniston, and Ali Larter chopped their layers into chic A-line cuts.

This one is on Princess Beatrice-the young royal made headlines when she appeared at her cousin's wedding in a Philip Treacy bow hat. In fact, the topper created such a stir that the 22-year-old was able to auction it off to benefit UNICEF and Children in Crisis for a not-insubstantial sum of $131,648. No strangers to major headwear themselves, both Sarah Jessica Parker and Lady Gaga have also recently been spotted in major Philip Treacy creations.

Abs are no longer relegated to the gym! Gwyneth Paltrow flaunted her midriff at the Emmys in a two-piece Emilio Pucci design. Jessica Biel and Jennifer Lopez also revealed the fruits of their personal training, each of them sporting bellybutton-baring Christian Cota separates.

Wow! These Michael Kors gowns brought more than just a pop of color to the red carpet, they made an all-over statement. Stunners like Heidi Klum, Rosie Huntington-Whiteley and Nikki Reed glowed in his tan-enhancing fluorescent brights.

Having second thoughts about your short crop? Take a tip from Jessica Alba, Chloe Moretz, Vanessa Hudgens and Selena Gomez, who transformed their short and shoulder-length hair into long layers overnight with the help of some last-minute extensions. At the press conference for the 2011 MTV Europe Music Awards, Bieber's BFF rocked a wavy chin-length cut, which turned into a lush, long ponytail in time for the awards show the very next day.

There's more! If you liked this gallery, you'll love:
amp#149;2011's New Style Stars
amp#149;Most Memorable Style Moments of the Year
amp#149;Most Stylish Men of 2011