In late 2015, the Kiernan Shipka-fronted horror-thriller The Blackcoat's Daughter premiered at the Toronto International Film Festival. It's been more than a year, and now, at long last, the film will reach wider audiences when it hits theaters next weekend. In the film, Shipka plays a 15-year-old woman attending a Catholic boarding school; when her parents fail to show up to pick her up for February break, she's left with a peer — played by Lucy Boynton — who fills her head with images of nuns as devil worshippers. And judging by early looks, it only gets grimmer and bloodier from there.

Mad Men alumna Shipka, as well as castmates Emma Roberts and Boynton, arrived in New York to premiere the film at an intimate screening with the Cinema Society ahead of its wide release. In contrast with the dark, brooding tone of the film, each young actress opted for bright, springtime colors: Roberts wore a lavender Chloé minidress, Boynton a cotton candy-pink Prada ensemble, and Shipka, the most fresh and floral of all, a long, flower-embellished Rosie Assoulin dress.

Kiernan Shipka in Rosie Assoulin at the premiere of The Blackcoat's Daughter in New York, New York, March 2017.

Dimitrios Kambouris/Getty Images

Who: Kiernan Shipka.

When: Wednesday, March 22.

Where: The premiere of The Blackcoat's Daughter with the Cinema Society in New York, New York.

What: A flower-patterned, floral appliqué-embellished gown by Rosie Assoulin from the designer's Fall 2017 collection.

Why: With Monday's vernal equinox, it's officially spring. No one seems to get that better than Kiernan Shipka, whose pop-art flower dress is practically a garden bursting with color. It's a stark contrast to the bloody horror film she's promoting, which makes it all the more welcome a statement. It has all the romance of Shipka's usual Dior fare with a more playful disposition. (During her presentation, Assoulin also showed trousers in the same textile. Absent from Shipka's look, though, were the tiny clay pot earrings an artisan was throwing in a corner of the presentation.) If this is what spring looks like, we're ready for it.

Kiernan Shipka weaves a tale of her Sweet Sixteen: