Costume design is rarely just about clothes. Sometimes, it’s a trap. When Emerald Fennell’s Promising Young Woman hit theaters, everyone expected a gritty, dark thriller draped in shadows and leather jackets. Instead, we got a pastel-colored nightmare. Cassie, played with a terrifying stillness by Carey Mulligan, spends the movie wrapped in soft mohair, floral prints, and DIY nurse costumes. It’s calculated. It’s jarring. Honestly, the promising young woman outfits are the most effective weapon in the entire film because they weaponize the "feminine" aesthetic to catch predators off guard.
Nancy Steiner, the costume designer who also worked on Lost in Translation and The Virgin Suicides, didn't just pick pretty things. She leaned into the "candy-coated" aesthetic to mask Cassie’s trauma. It’s a subversion. When you see a woman in a delicate rose-print dress, you don't think "vengeance." You think "approachable." That's the point.
The Psychology of the Pastel Palette
Why all the pink? Traditionally, bright pinks and soft blues signal innocence. They signal someone who isn't a threat. Cassie uses this like camouflage. Throughout the film, her wardrobe evolves based on who she is trying to deceive.
Take the "Coffee Shop Cassie" look. It’s basically the uniform of a girl who has given up, or at least wants you to think she has. She wears oversized, chunky knits and loose jeans. It feels relatable. It feels safe. But look closer at the colors. They are almost sickly sweet. Steiner used a lot of vintage pieces to give Cassie a sense of being "stuck" in time—specifically stuck at the age when her life was derailed.
Then there are the nighttime "traps."
These outfits are different. They aren't what Cassie actually likes; they are what she thinks men want to see. She plays various archetypes: the "drunk" girl in the office-ready blouse, the "club" girl in bodycon. There’s a specific scene where she wears a bandage dress that feels so dated it’s almost painful. It’s a costume of a costume. She is performing a version of femininity that makes men feel powerful, which is exactly when she strikes.
👉 See also: Is Heroes and Villains Legit? What You Need to Know Before Buying
That Iconic Nurse Costume and the Blowout Hair
We have to talk about the nurse outfit. It’s the climax of the movie. It’s also the most blatant use of promising young woman outfits as a tool of psychological warfare.
This isn't a medical uniform. It's a "stripper" version of a nurse, complete with a rainbow wig that looks like something bought at a 24-hour Halloween pop-up shop. It is deliberately cheap. It’s tacky. By the time Cassie reaches the bachelor party, she has fully leaned into the caricature. The contrast between the bright, multi-colored hair and the cold, clinical vengeance she’s seeking is enough to give anyone whiplash.
The hair is actually a huge part of the "look."
Cassie’s hair is almost always perfectly curled or braided. It’s "done." It suggests a level of effort and "niceness" that contradicts her internal state. Even when she’s at her most vulnerable, her hair is a shield of perfection.
The Subversion of the "Female Gaze"
Usually, in revenge movies, the protagonist goes through a "badass" transformation. Think Uma Thurman in the yellow tracksuit in Kill Bill. We expect the leather. We expect the combat boots. But Fennell and Steiner rejected that. They kept Cassie in florals.
- The rose-print "C" necklace: A tiny detail that screams "suburban girl."
- The gingham prints: They feel like a picnic, not a murder.
- The pigtails: A direct nod to infantilization.
This choice forces the audience to confront their own biases. If we see a woman in a floral dress and assume she’s harmless, we are part of the problem the movie is trying to highlight. The outfits are a mirror. They reflect the societal expectation that women should remain "sweet" regardless of what has happened to them.
✨ Don't miss: Jack Blocker American Idol Journey: What Most People Get Wrong
Why the Aesthetic Went Viral
Despite the dark subject matter, "Cassie-core" became a thing on TikTok and Pinterest. People were obsessed with the mix of soft textures and sharp edges. It tapped into the "Coquette" aesthetic before that term was even mainstream. But there's a disconnect there. To wear these clothes as a "vibe" without acknowledging the trauma they represent in the film is... complicated.
It’s interesting how we strip away the context.
We see a mohair cardigan and think "cute." We don't necessarily think about the woman wearing it as she stares at a wall, unable to move past a decade-old crime. The film uses fashion to illustrate how society consumes "pretty" things while ignoring the rot underneath.
Recreating the Look (With Caution)
If you're looking to channel the promising young woman outfits style, you’re basically looking for "Aggressive Femininity."
- Focus on the 1970s and 90s mix. Cassie’s wardrobe feels like a thrift store haul from two specific eras. Look for high-waisted denim paired with delicate, lace-trimmed tops.
- Pastels are non-negotiable. Lavender, mint green, and baby pink. The goal is to look like a French macaron.
- Contrast with the accessories. Use jewelry that feels personal, like the "C" necklace or tiny gold hoops.
- The Makeup. It’s either "no-makeup" makeup or smudged, slept-in eyeliner. There is no middle ground.
Steiner actually sourced many of the pieces from places like Zara and ASOS, mixed with genuine vintage. It wasn't about high fashion; it was about "real" fashion. It was about what a girl in her 30s living with her parents would actually be able to buy.
🔗 Read more: Why American Beauty by the Grateful Dead is Still the Gold Standard of Americana
The Cultural Impact of the Wardrobe
The costumes in Promising Young Woman did something most movies fail to do: they told a parallel story. You could watch the movie on mute and still understand Cassie’s descent just by looking at her hemline and her color palette.
As the movie progresses, the colors get slightly more washed out. The prints get smaller. By the end, she is almost blending into the background—until the nurse outfit happens. That final explosion of color is her final act of defiance. It’s loud because she’s done being quiet.
Actionable Takeaways for Your Wardrobe
Fashion is a language. Whether you're dressing for a job interview or a night out, you're sending signals. Promising Young Woman teaches us that those signals can be manipulated.
- Audit your "safe" clothes. Look at your wardrobe and identify which pieces you wear when you want to disappear or look "unthreatening."
- Experiment with subversion. Try pairing something hyper-feminine, like a floral dress, with something traditionally "hard," like heavy boots or a sharp blazer.
- Use color intentionally. If you need to command a room, maybe skip the pastels. If you need to de-escalate a situation, soft textures and lighter colors actually do have a psychological effect on how people perceive your aggression levels.
The legacy of these outfits isn't just about the clothes themselves. It’s about the realization that "looking like a promising young woman" is often a performance. Sometimes, it's a performance for survival. Other times, it's a performance for revenge. Either way, the clothes are never just clothes.
Next Steps for Deepening Your Style Strategy:
- Review the Color Wheel: Study how pastel shades affect mood and perception in social settings.
- Vintage Sourcing: Search for 70s-era floral midi dresses to capture the authentic Steiner-inspired silhouette.
- Analyze Costume Design: Watch Steiner’s previous work in The Virgin Suicides to see how she uses soft lighting and fabrics to convey repressed emotion.