Katy Perry wore our favorite look of the night at the 23rd amfAR Cinema Against Aids Gala on Thursday, May 19th. Katy looked ravishing in a red flamenco inspired Marchesa gown adorned with rose petals on the red carpet in Cannes. The Fireworks singer accessorized with Harry Winston cluster diamond chandelier earrings and a Lotus cluster diamond ring. She completed her look with a bold red lip and a sleek hairdo. Katy changed into a gold outfit with 10 carat diamond Harry Winston earrings and a 12 carat carpet diamond ring for her live performance which included a medley of her hit songs.

Katy's on-again-off again boyfriend Orlando Bloom also attended. The pair sat at separate tables throughout the event. Katy later changed into a chic silver outfit for the after party in the South of France. Uma Thurman hosted the event in a pink Schiaparelli couture gown, which raised over $170 million dollars for charity. The night featured Leonardo DiCaprio auctioning off a pricey week long stay at one of his properties. The Cannes Film Festival came to an end on Sunday, May 22 awarding Ken Loach's drama "I, Daniel Blake" with the Palme d'Or.

Bella Hadid was glam in a Dior gown on the carpet which was more demure than the headturning red Alexandre Vaulthier gown she wore on May 18th. Later that evening, Bella wore an open shirt with plenty of double sided tape for the Studio 54 inspired charity fashion show. Harry Winston also provided its exquisite fine jewelry for the spectacular Disco Collection Fashion Show, which was curated by Carine Roitfeld.

Harry Winston served as one of the night's presenting sponsors and also donated the Secret Cluster perfume bottle necklace. Karolina Kurkova smoldered in Armani Prive while she modeled the necklace set with aquamarines and sapphires exclusively for the amfAR Cinema Against AIDS 23 live auction, which received a final bid of 375,000 Euros. The Secret Cluster Perfume Bottle Necklace, featuring 452 diamonds, weighing a total of 17.27 carats; and 12 sapphires and aquamarines, weighing a total of 2.85 carats, set in platinum.

Who wore Harry Winston jewels: Alessandra Ambrosio in a diamond necklace. Barbara Palvin in River diamond earrings and a Lotus diamond ring. Irina Shayk in a WInston cluster diamond necklace and secret cluster diamond bracelet.

Check out all the best looks from the amfAR red carpet.

What They Wore: Heidi Klum donned a yellow Versace formal dresses perth with a plunging neckline, She accessorized with over $6 million in Lorraine Schwartz diamonds and turquoise jewels. Supermodels Karlie Kloss and Chanel Iman wore Marchesa gowns. Karlie paired her off- the-shoulder dress with Harry Winston secret wonder diamond earrings. Dakota Fanning was in Valentino. Alessandra Ambrosio, Jourdan Dunn wore black LBD's. Alessandra exposed the thigh high side slit in her Redemption gown . Jourdan accessorized her DSquared2 gown with a y-shaped yellow diamond Harry Winston necklace. Rosie Huntington-Whiteley wore a super sexy Galvin for Opening Ceremony gown. Cannes juror Kirsten Dunst and Vanessa Paradis wore Chanel. Lara Stone was in Givenchy. Irina Shayk was in Miu Miu, Doutzen Kroes wore Tom Ford. Barbara Palvin was in Armani Prive. Lais Ribeiro was in Sophie Theallet. Sasha Luss was in Balmain Dame Helen Mirren paired her black gown with a Harry Winston jewels which included a Lily cluster diamond necklace and yellow earrings.

Who was there: Ariana Lima, Kirsten Dunst, Elle Fanning, Doutzen Kroes, Irina Shayk, Nina Agdal, Natasha Poly.

Since 1932, Harry Winston designs have drawn from the infinite beauty of nature to inspire breathtaking works of timeless brilliance. The Secret Cluster Perfume Bottle with Sapphires and Aquamarines, designed exclusively for amfAR’s Cinema Against AIDS 23, pays tribute to this time-honored tradition by exploring the extraordinary wonders of the world’s most precious elements – rare gemstones and water – with a one-of-a-kind necklace that recalls the brilliant blue hues of the azure sea. This spectacular creation seamlessly captures our founder’s historic appreciation for the beauty of the world that surrounds us, and furthers our commitment to transforming exquisite gemstones into brilliant works of art. Set in platinum, fancy shaped diamonds and rare gemstones in shades of blue – from deep sapphires to icy aquamarines – delicately drape around a hand-carved 1.5ml rock crystal vial, perfect for one’s own preferred fragrance.

In January 2015, Harry Winston announced a groundbreaking three-year partnership with amfAR, in support of the organization’s mission to end the global AIDS epidemic through innovative research, and its “Countdown to a Cure” initiative, which is aimed at developing the scientific basis for a cure by 2020. Launched in February 2014, the Countdown is designed to intensify amfAR’s cure-focused HIV research program through strategic investments of $100 million over the next five years.

Harry Winston’s support for amfAR marks the Brand’s first collaboration with a global organization, signifying not only its expanding presence, but also its increased philanthropic commitment to vital causes that continue to affect millions of people worldwide. In honor of its second year of partnership with amfAR, in February 2016, Harry Winston introduced the Countdown to a Cure Timepiece – a limited edition collection of 20 men’s and 20 women’s models. Retailing for $21,200 for the men’s timepiece, and $16,200 for the women’s, the Countdown to a Cure Timepiece is sold exclusively at Harry Winston salons worldwide, with 20% of the retail sales price from each limited-edition timepiece benefitting amfAR’s efforts to develop the scientific basis of a cure for HIV by 2020.Read more at:http://www.marieaustralia.com/red-formal-dresses