Lady Gaga knows how to stick out — at events, concerts and now … on her film set, where her orange hair was hard to miss.

The usually blonde Gaga went carrot top on the “A Star Is Born” set this week. The Bradley Cooper-directed film was shooting Wednesday in L.A. … and the ginger look is something new for the remake.

Gaga’s role was previously played by Judy Garland and Barbra Streisand, neither of whom went red.

We looked … Gaga’s had orange hair before, so nothing new for her. Just a regular day at the office.

EXCLUSIVE

Christina El Moussa‘s pissed her good looks are being used to hawk an anti-aging product — she’s only 33, but she says the real issue is she never endorsed it … so now she’s threatening to sue.

Christina’s name popped up in an online campaign claiming she’s the face of a skin care product line that’s made her rich beyond her wildest dreams. It’s one of those Internet ads you see dozens of times a day, but Christina says it’s straight-up #fakenews — all the quotes attributed to her are completely made up.

She’s fired off cease and desist letters to a ton of companies and individuals warning them to take down the stories, or she’ll sue. The problem is it’s hard to track down exactly who’s behind the campaign. Different versions keep popping up, but all have the same message: Christina’s behind these skin products, buy here.

Policing the Internet’s no easy task, which is why she’s had to send the letter to 23 different companies or individuals. So far.

EXCLUSIVE

UFC strawweight Michelle Waterson — aka the Karate Hottie — doesn’t like that fellow UFC fighter Pearl Gonzalez had to jump through hoops to get cleared to fight with breast implants … and says all women with fake boobs should be allowed to fight.

The NY State Athletic Commission conducted a review into Gonzalez before UFC 210 once they learned she had implants — but ultimately cleared her to fight.

Waterson — who’s fighting Rose Namajunas this weekend at UFC on FOX — says breast implants are no big deal … and as long as the fighter makes weight, she doesn’t think there’s any real problem.

Of course, the commission says it is looking out for the health of the fighter (we’re guessing to make sure there’s no risk of the implant popping) … but Michelle seems to think there’s no real concern.

Chrissy Teigen just helped one aspiring skin care expert by taking a huge load off her shoulders … she’s paying for the student’s tuition.

The student, a woman named Mercedes — a self proclaimed skin care expert – recently reached out to her friends and family asking for help to pay a $6k tab for classes in order to get a license in esthetics and further her knowledge in skin care.

Luckily for Mercedes, Chrissy came across her posting and plunked down $5,605 … the remainder of the balance with a message, “I’ve seen this be your passion for such a long time now. So excited to see you fulfill your dream!”

Awesome move.

EXCLUSIVE

Look out, Sex Panther … Floyd Mayweather is now looking to conquer the smell game.

TMZ Sports has learned Mayweather Promotions filed a petition with the U.S. Patent and Trademark Office to use “TBE” (The Best Ever) for cologne, perfume and other cosmetic and skin care products. 

Floyd’s a big fan of self-pampering … so it sorta makes sense. 

Sources close to Mayweather tell us the plans are only in the beginning stages — so don’t expect TBE to hit the perfume counter anytime soon. 

If it does come to fruition, Floyd will join an elite club of jocks with their own signature scents — including Michael Jordan, David Beckham, Cristiano Ronaldo and Zlatan Ibrahimovic. 

Kristen Stewart got rid of her mop in favor of a blonde buzz cut.

The “Personal Shopper” star unveiled her new hairdo Tuesday at her movie premiere in L.A. … and gotta say — we dig it.

EXCLUSIVE

Kanye West wants to go head-to-head with his famous sister-in-law … diving head first into the cosmetic biz dominated by Kylie Jenner.

Kanye’s filed legal docs declaring his intention to produce DONDA brand makeup, perfumes, lotions and other cosmetics. Donda, of course, is Kanye’s beloved mom who passed away in 2007.

He’ll be up against some stiff family competition. Kylie’s cosmetics sell out within minutes … some resell on eBay for 10 times the retail value.  

Kanye’s application to snag the DONDA cosmetics line is currently being processed but our sources say at this time he’s only filed the paperwork in case something develops. 

He’s made it clear … Kanye wants to be the new Martha Stewart, creating a lifestyle brand that includes credit cards, cars, wallpaper screens, furnishings, video games, amusement parks, hotels, fitness centers and healthy fast food.

So which one’s gonna give Kim lip?

EXCLUSIVE

Fabolous has put his money where his mouth is by dropping $40k to fix his teeth, and the before and after pics show it was worth every penny. 

Loso has rapped about the chip in his front tooth on 2001′s “Right Now & Later On,” and hinted he’d get it fixed, and that’s just part of his dental woes.

He went full dental just before New York Fashion week and left with a set of 10 new veneers on his top grill.

NY dentist Mojgan Fajiram usually charges around $4k per veneer, so it definitely adds up. 

As for the timing… we’re told Fab wanted to treat himself to a belated 39th birthday gift. 

EXCLUSIVE

One of Kylie Jenner‘s eye kits has become a real pain for customers who’ve filed complaints about chemical-induced headaches.

At least 15 people filed complaints within the past 2 weeks with the Better Business Bureau, claiming they smelled “chemicals and glue” when opening Kylie’s Royal Peach Eyeshadow Palette.

Customers described the odor as “spray paint” or “paint thinner,” and one said it stunk so bad she put the whole package outside her house. There’s also at least one complaint of the makeup causing “a horrible headache.”

The BBB tells us Kylie Cosmetics launched an investigation immediately and found an adhesive in the packaging was causing the smell. Kylie’s company insists it’s safe to use … according to the BBB.

No word if the packaging has been changed, but the BBB says it got fewer complaints this week. We reached out to Kylie Cosmetics … but no word back.