I Saw J.Lo and Sienna Miller Wearing This Exact Colour With Flares—It's Going to Be Huge This Summer
J.Lo and Sienna Miller agree—there's something about an elegant light blue layer that pairs so well with flares.


If you've been paying attention to the current fashion cycle, then you'll have probably noticed that there are a few key colour trends getting a lot of love in 2025. It will surprise no one to hear that butter yellow is decidedly "in" and that chocolate brown is still enjoying a moment in the sun. While these two shades have earned places in my wardrobe, next it’s the soft, elegant and entirely summer-ready baby blue tone that I'm interested in.
A serene shade that feels at home amongst the pretty colours that dominate a summer wardrobe, this emerging colour trend has been quietly settling into some of the chicest wardrobes out there—including, most recently, in Jennifer Lopez and Sienna Miller’s. Both stepping out in the same pastel blue layer, it wasn’t just the colour that caught my eye, but exactly how they’ve styled the colour for the new season. Rather than throwing the colour into any ensemble, both Lopez and Miller built their looks around one key combination: a baby blue jacket worn with flared jeans, creating a pretty early summer ensemble.
The jacket in question—Chloé's pleated jacket (£2,180)—is tailored with plenty of pleats, lending the garment a voluminous finish that is neatened by the cropped cut and sleek single-breasted finish. Leaning into the elegant, dreamy aesthetic, Lopez paired her Chloé jacket with high-waisted, flared jeans in a rich blue shade, relying on soft pink and lilac accents seen throughout her bag, shoes and blouse, further creating an interesting colour palette.
Although this pairing feels ultra-current, Miller actually debuted a similar look back in September at Chloé’s spring/summer 2025 show, styled with blush suede flares, oversized sunglasses and stacks of boho jewellery—a sign that this trend has been slowly building to take off just in time for summer.
With two of my favourite style icons already co-signing the blue jacket and flares look, I expect that it won't be long until we're seeing this elegant combination everywhere. If you're also inspired by this emerging trend, scroll on to shop the best blue jackets to know about this season.
SHOP THE JACKET TREND HERE:
SHOP OUR OTHER FAVOURITE BLUE JACKETS HERE:

Natalie Munro is Who What Wear UK’s news writer and has worked in the fashion industry since she graduated with a degree in Journalism from the University of the Arts London. Natalie’s experience in the industry spans journalistic and styling roles that have seen her work for publications including British Vogue, Conde Nast Traveller, Vogue Ukraine, AnOther Magazine and Elle UK.
With an interest in uncovering the latest fashion trends, Natalie takes a leading role in identifying news for Who What Wear UK. Reporting on a daily basis, Natalie focuses on trends on and off the runway, as well as street style and celebrity fashion. Natalie also creates content for Who What Wear’s social channels including TikTok and Instagram on a weekly basis.
-
Forget Flats—Everyone With Good Taste Is Wearing These Boots With Jeans and a Jacket
Put these on your shopping list.
-
It's True: The Best (Real) Suede Finds of the Season Are From Zara, Mango, and More
No need to overspend.
-
My Mom Is in Her 50s and Asked Me for Fashion Advice—8 Chic Nordstrom Outfits I Put Together for Her Under $425
Outdated prints and "ugly" shoes included.
-
Consider This Your Heads-Up: The Coolest People in Fashion Are Already Wearing This New Elegant Outerwear Brand
Founded and designed by celebrity stylist Rob Zangardi.
-
This Is the Low-Key Color Trend People Are Suddenly Wearing More Than Camel
Even Jennifer Lopez.
-
Nordstrom's Fall Sale Is Almost Over: Tory Burch Shoes and Ralph Lauren Jackets to Shop Before It Ends
Only two days left.
-
Why Did I Wait So Long to Buy Into This Rich-Looking Jacket Style?
Now, it's in my fall rotation.
-
If You've Already Ordered This Pretty Winter Trend Celebs Just Started Wearing, You Have Good Taste
Spotted on It girls in Paris and NYC.