When it came to accessorizing her newly platinum do for Sunday’s Grammy Awards, the always-edgy Rihanna went for some depth at the root, plunging Armani — and seriously pricey digits!

Sporting Red Carpet Manicure’s “Amor 24,” a 24-karat gold polish that retails for a whopping $5,000, the performer also added tiny dollar signs to her pinky fingers.

Brand reps tell us that upon spotting the gilded lacquer, Rihanna promised to “guard it with her life.”

Additional limited edition bottles of “Amor 24″ will be auctioned off for charity, but a more affordable version, “Award Winning,” will be available this spring on RedCarpetManicure.com for $9.99.

–Justine Harman

WANT MORE? COOL WINTER NAIL TRENDS TO TRY RIGHT NOW!

New week, new haircuts! Demi Lovato and Miley Cyrus both changed up their hairstyles (again) last week, sharing photos of their new looks on Twitter.

Lovato — a natural brunette who was most recently a redhead — went blonde Saturday. “Thank you SO much Nine Zero One salon for my new locks,” she wrote, asking fans for feedback. They must’ve liked the look: later that day, she Tweeted, “Haha Demi Blondevato is a trending topic?!! Y’all are funny!”

Cyrus’s change was a bit more subtle: the singer, who took five inches off of her hair last month, went a bit shorter and added some face-framing layers. Her Tweet of “You likey?” was met with compliments like “fab” and “beautiful” from adoring followers.

We love both ladies’ new looks, but want to hear what you think. Tell us: Do you like Lovato and Cyrus’s new dos?

Courtesy Miley Cyrus

TRY STARS’ STUNNING HAIRSTYLES IN OUR ‘INSTANT MAKEOVER’

Leave it to Madonna‘s daughter to try a cool new look! Lourdes Leon stepped out on her way to school in New York Thursday, sporting a funky new half-shaved do. The stylish 15-year-old — who’s had long dark hair forever — had her hair up in a bun, bringing extra attention to the edgy style.

Leon hasn’t made drastic changes to her hair before, though she’s toyed with the idea. “I want royal blue hair but not a streak, like my entire head,” the teen designer wrote on her blog in December of 2010.

But at the time, she wasn’t so sure she’d get away with the change. “I read this blog aloud to my mother,” she continued, “and she is sitting here staring at me with no expression on her face, as if she doesn’t approve of it!” Wonder if Madonna gave this cut the OK? Tell us: What do you think of Leon’s look?

SEE THE STARS’ WACKIEST WINTER HAIRSTYLES

Best known for her spitfire sense of humor and otherworldly good looks, Olivia Wilde’s stay-gorgeous routine is surprisingly girl-next-door.

“[I wash] and moisturize my face with drugstore brands like Cetaphil and CeraVe,” she tells PEOPLE.

And when that newly lopped do becomes a hassle, the TRON star looks to easy solutions. “I’m into cool stretchy headbands,” she says. “I throw it up and try to make it look interesting and put on a headband and then it looks like it was all intentional.”

While her beauty basics are decidedly simple, Wilde’s fitness routine runs the gamut from the serious to the silly. “I need kind of Ashtanga, like good, serious yoga,” she explains. “I never feel more beautiful than after I’ve really spent some time breathing.”

But when downward dog isn’t cutting it: “Hula hooping is one of those things that everybody sort of scoffs at,” she adds semi-seriously, “but I know people who have lost serious weight hula hooping.”

To learn more about the Revlon ambassador’s basic and bodacious beauty booty (can you say wasabi eye drops?), pick up the newest issue of PEOPLE, on stands now.

–Justine Harman with reporting by Pamela Edwards-Christiani

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It’s officially a trend! Rachel McAdams is the latest star to add bangs to her hairstyle, debuting the look at the Los Angeles premiere of The Vow (sponsored by Ralph Lauren Romance) Monday night. The star stepped out in a sky-blue Vivienne Westwood dress and glimmering jewels, complementing her look with smoky eyes, red lips and her new blonde bangs.

McAdams joins a growing list of leading ladies who’ve added bangs to their hair recently, including Jessica Biel, Rose Byrne, Cameron Diaz (sometimes), Olivia Wilde, Kim Kardashian (who tried clip-ons) and Reese Witherspoon, who cut them to cover a forehead scar. Kelly Clarkson rocked them during the Super Bowl, and Sarah Michelle Gellar added a few face-framing bangs recently, as well.

We think McAdams always looks lovely, but want to hear your thoughts. 

CHECK OUT THE STARS’ WACKIEST WINTER HAIRSTYLES

With her hair constantly at the mercy of curling irons, straighteners and blow dryers, Nicole Scherzinger relies on hydrating products to keep her hair healthy. And now, she’ll likely have a lot of them at her disposable: the singer and former X Factor judge is the newest face of Herbal Essences.

“It’s amazing,” she tells PEOPLE of the new gig. “I have a big grin on my face and I’m glowing. I’m really proud to be partnered with this brand.”

Courtesy Herbal Essences

Though Scherzinger calls her “super-long” hair “strong,” she says it’s often hard to take care of because it is subjected to so much heat styling. “I always have to change hairstyles, whether it’s being on TV one minute to being on stage the next, then going to dinner or a meeting,” she explains. “It’s important to keep it hydrated, and use the right products to protect it from the heat.” To that end, she credits Herbal Essences’ Hello Hydration, Hydralicious and Long Term Relationship with locking in moisture and preventing split ends.

When she’s enjoying a day off, Scherzinger generally gives her hair a break, letting it air dry before tossing it up in a bun. But she’s no styling amateur herself: the day of her Herbal Essences shoot, the singer was even giving her glam squad advice. “I know all the mousses, honey,” she shares. “Normally people associate mousse with perms, but with this hair, are you kidding me?! Mousse equals volumizing.”

Scherzinger will appear in Herbal Essences’ print ads as well as commercials — some of which will feature her music. “It’s what I’ve worked so hard for my whole life,” she says. “Not only to have music as my driving force, but to build my brand and be associated with products I believe in — those that are a direct reflection of who I am.”

–Kate Hogan

TRY ON THE LATEST STAR HAIRSTYLES IN OUR ‘INSTANT MAKEOVER’

It wasn’t just about planking; Katy Perry‘s recent stint as a mermaid had to do with her latest series of ads for haircare line ghd. The singer channels Little Mermaid Ariel in her new U.K.-only campaign, (ironically) advertising a hair dryer from below sea level.

“I love it because I’m such a fan of the Disney movies,” the newly single star says of her campaign, shot by David LaChapelle. “Ariel is such a big influence. It’s always fun to dress up once in your lifetime as a mermaid and have that fish fin tail.”

The glimmering “tail” Perry wears in the photos was custom-made by a Dubai-based designer, but the singer’s favorite part of the look seemed to be wearing the lavender wig. “It was fun,” the blue-haired star shares. “It’s as if Lisa Frank had done The Little Mermaid.”

So should we expect to see Perry — who explored past decades in her last round of ads — donning a mermaid costume on her next tour? “I would wear it again,” she says. “I actually thought about wearing it for Halloween.” Tell us: What do you think of Perry’s aquatic ad?

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We all know Rihanna can Talk That Talk, but who knew she was a Gossip Girl too?

When the singer debuted a sneak peek at her new platinum do (which she’ll sport on an upcoming cover of ELLE), we couldn’t help but think of another towheaded trouble maker: Taylor Momsen.

With that chunky fringe and stained pout (not to mention that major ‘tude!), Rihanna is the spitting image of a good Upper East Sider gone bad.

But while the look may not be permanent (as we all know, she’s quite the quick change artist), it’s not exactly temporary either: “bleach + weave” she Tweeted a curious fan. Tell us: Who looks better with a platinum fringe?

–Justine Harman

SEE MORE DARING LOOKS IN: STARS’ WACKIEST WINTER HAIRSTYLES

Nearly 84 percent of StyleWatch readers said they love Reese Witherspoon‘s new bangs, but there’s a somewhat dark reason behind the star’s new hairstyle. During an interview with Graham Norton, airing Saturday night on BBC America, Witherspoon reveals details about her recent car accident — and the scar it left behind.

“I was jogging and I got hit by a car,” she shares. “They said I am very hard-headed because I landed right on my head and I have a scar, hence my new hairdo. I don’t remember much about it but miraculously and thank God, I am fine.”

Though she didn’t press charges against the driver, an 85-year-old woman, there were legal repercussions. “They took away her license and gave her a bus pass,” the actress explains.

Moving into lighter territory, Witherspoon — who stars in the upcoming romantic action comedy This Means War — reflects on her stellar 2011, which included her wedding to Jim Toth and a meeting with the Duke and Duchess of Cambridge. “It was really fun,” the actress shares. “[Kate] was lovely and funny and she said some sweet girly things. I think she is handling herself so beautifully.”

–Kate Hogan

Bieber called: he wants his swoosh back! Though the pop star’s once-iconic hairstyle is no more, Juno star Olivia Thirlby is picking up where he left off, trading her long brunette locks for a feminine version of his cut. Popping up at the Sundance Film Festival in Park City, Utah, last week, the starlet showed off her new look, which references Bieber’s with its bowl-ish shape and sweeping bangs. She’s got the perfect face for a pixie, but we want to know what you think. Tell us: Are you loving Thirlby’s Bieber-esque haircut?

VOTE NOW ON MORE STAR HAIR CHANGES

Despite her influential pixie and daring red carpet acumen, Emma Watson doesn’t consider herself glamorous.

“My problem is that I am a little bit boring,” she admits to French Elle. “I don’t wear designer bags or big sunglasses.”

And regardless of access to designer duds, the Harry Potter star’s downtime is underscored by a more casual approach to fashion: “When I don’t have to play Emma Watson in public, I’d rather not put myself out there,” she explains. “I have to be more careful with my look in my everyday life.”

But what about those ubiquitous Lancôme beauty ads? “Someone asked me why I accepted this job, as I wanted to stand in the shadows,” she says. “Actually, I gave up the idea that I could [ever] become anonymous again!”

–Justine Harman

CHECK OUT MORE STAR STRANDS IN: ’10 HAIRDOS THAT TURNED HEADS!’

With her flawless skin and luminous locks, it’s hard to believe the Courteney Cox is in fact, 48 years old.

Good thing xoJane.com enlisted the star to once again dispense tricks of the trade. “Hair is a tough one,” she admits. “I’m pretty lazy. I don’t even know how to use a blow dryer.”

To achieve trademark on-set loose curls, she refers to her Cougar Town guru, Brant Mayfield, who wraps big sections with a $130 Clipless Enzo Milano curling iron. To prepare for heat, he uses $27 Bumble and bumble Thickening Spray to add texture to just-washed hair.

“When your hair is dry from frequent blow drying, try a $16 Moroccan Oil treatment,” Cox advises. “It’s made of argan oil which is very nourishing and conditioning.” Other faves include $8 one-and-you’re-done lip moisture from Acca Kappa. “It really stays on and also has an SPF. I like the vanilla flavored one,” she gushes.

A self-professed former “sun worshiper,” the star relies on $85 NIA 24 Niacin-Powered Skin Therapy to help with hyperpigmentation and to improve skin’s texture and tone. “I’m actually a fan of all their products,” she says. “Their sunscreen is great!”

–Justine Harman

CHECK OUT THESE TRESS TRANSFORMATIONS: STARS’ WACKIEST WINTER HAIR!

Another day, another hair change for Kim Kardashian. The reality star dyed her hair Sunday, posting a photo to Twitter on Monday.

“I dyed my hair lighter yesterday! I’m loving it,” the soon-to-be divorcée wrote. “New hair color=new beginnings for me. You like?”

Kardashian, who added clip-on bangs to her hair earlier this month, dyed her hair a similar shade of brown last summer. “I feel younger,” she wrote at the time. Her colorist, Rebecca Friedman, told PEOPLE that the look gave the star “more dimension,” too. While we love Kardashian’s hair color, we have to admit: it doesn’t look that different to us! What do you think?

SWITCH UP YOUR HAIR COLOR IN OUR INSTANT MAKEOVER

Are bangs the hottest hair accessory of 2012? Headbands aside, it sure seems that way. Jessica Biel is the latest star to try the trend, stepping with former 7th Heaven costar Beverly Mitchell on Sunday with a sleek new do.

Biel follows in the footsteps of Taylor Swift and Reese Witherspoon, both of whom cut bangs recently. Olivia Wilde and Cameron Diaz debuted side-swept styles, too, while Kim Kardashian tried clip-ons during a New Year’s bash. And we’re only through January! Tell us: What do you think of Biel’s bangs?

TRY STARS’ TRENDY HAIRSTYLES IN OUR ‘INSTANT MAKEOVER’

Rose Byrne gave us a lot to look at during Sunday night’s Screen Actors Guild Awards: her gorgeous face, for one, but also her interesting white jumpsuit and face-framing bob. So we had to ask: What was the story behind her look?

“I tried this on a couple of years ago,” Byrne told PEOPLE of her glimmering Elie Saab jumpsuit. “I loved it for an event and it just didn’t end up being the one that I wore. But I always had it in my mind.”

Once she decided she wanted to wear pants to the SAGs, Byrne called up her stylist, Penny Lovell, who immediately knew which look to pull. “[She] was like, ‘How about that great jumpsuit we tried on from Elie Saab?’” Byrne recalled. “And I was like, ‘Oh that? Let’s go!’ So that was it. I love jumpsuits.”

Though Byrne’s bob was somewhat old news by comparison — she first cut it several months ago — the actress had the look freshened by John Frieda stylist Harry Josh before the awards (her makeup was by Joe Fresh Beauty). “Just yesterday, he did another cut and he did the back and then he did the bangs again,” she explained during the SAG Awards Gala at the Shrine Auditorium. “It’s Scarface-inspired. It’s like Scarface meets Anna Wintour.” Tell us: What did you think of Byrne’s look?

–With reporting by Jessica Wedemeyer

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When a girl’s in Paris, she’s gotta have a trés chic haircut. Thankfully, Reese Witherspoon was up to the task Thursday, debuting wispy new bangs (and wearing a Theodora & Callum scarf) while arriving in the City of Light.

This isn’t the first time the actress — who turned up at the Golden Globes this month with sexy, voluminous hair — has cut bangs: shortly after splitting from husband Ryan Phillippe, she arrived at the 2007 Golden Globes with a hot new haircut (and that memorable Nina Ricci dress). “I felt like I looked different than I’ve ever looked,” she told ELLE of that red carpet moment. “I don’t know why. I just did.”

Though bangs are usually a small change, for Witherspoon, they’re kind of big news: the most major hair modification she’s made in recent months was a subtle post-wedding trim. Tell us: Do you like Witherspoon’s new bangs?

TRY ON THE BEST STAR HAIRSTYLES IN ‘INSTANT MAKEOVER’

When Cameron Diaz left her long hair behind this month, one would’ve assumed she lost some styling options in the process. But the actress is showing just how versatile a short cut can be, wearing her hair four different ways in as many days while out in Paris this week.

On Tuesday, before the Armani Privé fashion show, Diaz parted her platinum do from the side (top left), tucking loose ends under her ear. The day before, the actress popped by the Dior show sporting an easy updo (top right), with her roots teased and her ends neatly pinned on the back of her head.

Before Monday’s Versace show, Diaz displayed yet another look, this one a sleek, style that gave her roots lift and left her ends slicked at the back of her head (bottom left). But our personal favorite is her latest, which she wore to Valentino’s Thursday show: a feminine, slightly curled look with long bangs and lots of volume. Tell us: Which of Diaz’s hairstyles is your favorite? If you have short hair, how do you style it?

TRY STAR HAIRSTYLES FOR YOURSELF IN OUR ‘INSTANT MAKEOVER’ TOOL

–Check out a teaser clip for Victoria Beckham’s girly new dress line, coming soon [YouTube]

–Which stars are hanging out at Paris Fashion Week? Find out! [FabSugar]

–See all the looks from the Karl by Karl Lagerfeld collection for Net-a-Porter [The Cut]

–Hunger Games star Jennifer Lawrence‘s new reddish hair was a “happy accident” [InStyle]

–Is “imperfect” makeup the hot new beauty trend? [New York Times]

What would Miranda say? Cynthia Nixon recently went bald for her role as a cancer-stricken professor in the new Broadway play Wit, and showcased her newly shorn head on LIVE! with Kelly Tuesday morning.

“I thought it was going to be kind of no-muss, no-fuss, but I have to shave it every day,” Nixon revealed. “It’s got kind of a five o’clock shadow. You don’t want to go out with that.”

When host Kelly Ripa complimented Nixon on the shape of her head, the actress admitted that she wasn’t sure she’d be able to pull the look off at first. “I was always kind of curious to see what it would be like,” she shared. But once the play is over, don’t expect her to keep up with the daily shaves. “I don’t think I’m going to keep it forever,” she added.

Wit tells the story of Vivian Bearing, a poetry professor “at the top of her profession,” Nixon explained. After receiving a cancer diagnosis — which Nixon, a breast cancer survivor, can relate to — Bearing “goes through this really heavy-duty chemo,” Nixon said. “She meets that challenge, but she learns a lot about herself.” The play is in previews, and opens officially on Jan. 26.

–Kate Hogan

CHECK OUT STARS’ WACKIEST WINTER HAIRSTYLES

Her mom hated her gray hair — so Kelly Osbourne went ahead and made it purple. The reality starlet hit the red carpet at the Los Angeles Gay & Lesbian Center Honors Monday night sporting a subtle new hair hue — her second change in two weeks’ time.

Earlier this month at the People’s Choice Awards, Osbourne explained her unusual hair color choice to PEOPLE. “I can’t keep bleaching my hair and I want to grow it,” she shared. “So I take breaks in between.”

But last week at the Art of Elysium gala, Osbourne admitted she really loves changing her look. “I think that I have an addiction to dying my hair, because I always like it to be different,” she said. “I don’t like being compared to other people.”

So while her hair may be a bit fragile these days, Osbourne doesn’t seem to mind. “I don’t want to break this addiction, I love it,” she shared, pointing out one key benefit of frequent color changes: “I get a new look every day.”

–With reporting by Reagan Alexander and Dahvi Shira

CHECK OUT STARS’ WACKIEST WINTER HAIRSTYLES