Fashion Rose Byrne Wore the Springiest of Spring Dresses and It Was Awesome Welcome to "Who Won Fashion Today," where we award the boldest, best dressed person of the day. Winning fashion doesn't necessarily mean you're wearing the most expensive, trendiest, or prettiest dress. Rather, we reward risk-takers—those that stay true to their personal style and make us go, "Now THAT is a LEWK." By Ruthie Friedlander Ruthie Friedlander Twitter Ruthie Friedlander is a New York-based writer, editor, and founder of the At Large Agency. She is also the co-founder of The Chain, a non-profit eating disorder support system for women in fashion and entertainment. InStyle's editorial guidelines Updated on April 19, 2017 @ 11:15AM Pin Share Tweet Email Photo: Bennett Raglin/WireImage In HBO’s The Immortal Life of Henrietta Lacks, Rose Byrne plays the role of Rebecca Skloot, an investigative journalist working to uncover the story of Henrietta Lacks, a woman whose cells were used to create the very first "immortal" human cell line. If you’ve watched the trailer, you know two things: First, the all mighty Oprah Winfrey is the other star of the movie. Second, this is one chill-inducing, powerful flick. See Oprah Winfrey in the Immortal Life of Henrietta Lacks Trailer So what do you wear to the New York premiere of a serious film that co-stars arguably the most famous person in the world? Do you go demure, in a sleek black dress? Old Hollywood, in something gold and mermaid shaped? How about NO! How about you go fun, flirty, seasonal, and lighthearted? VIDEO: The Crazy Cost of a Lifetime of Makeup That’s exactly what the wonderful (and btw hilarious) Byrne did last night when she arrived at the premiere in a frilly floral Rosie Assoulin number from the designer's fall 2017 collection. Wearing a Rosie dress takes gusto: Her voluminous, highly patterned, bright pieces are best complimented by a big personality … which is exactly why Byrne shined so bright in this look. Never afraid to play with color, her stylist (Penny Lovell) paired the vibrant dress with a pair of Jimmy Choo suede purple pumps and a white clutch. Dimitrios Kambouris/Getty Another key accent? Her Selim Mouzannar Cluster Ring (available here). Swoon.