Cannes 2015: Lupita Nyong’o is belle of the fashion ball

Karlie Kloss wore a Tom Ford stone bugle bead grid embroidery sleeveless gown with choker detail to the amfAR Cinema Against AIDS Gala in Cap d’Antibes, France, on May 21.

Chanel Iman wears a Zuhair Murad Couture long-sleeve nude silk tulle evening gown with plunging décolleté and train featuring white flower appliques and silk thread embroidery to amfAR’s Cinema Against Aids Gala at the Cannes Film Festival on May 21.

A full look at Chanel Iman’s dress at amfAR’s Cinema Against Aids Gala at the Cannes Film Festival on May 21.

Model Sara Sampaio wears an Alexandre Vauthier black sleeveless gown with embellished neckline while at amfAR’s Cinema Against AIDS Gala at the Cannes Film Festival on May 21.

Another look at Kendall Jenner’s outfit at the May 21 amfAR Cinema Against AIDS benefit at the Cannes Film Festival.

Another look at Sara Sampaio’s dress at the May 21 amfAR Cinema Against AIDS benefit at the Cannes Film Festival.

Model Karlie Kloss chose this Louis Vuitton number for the “Youth” premiere at the 68th Cannes Film Festival on May 20.

Actress Jane Fonda dressed in Schiaparelli Haute Couture and Cartier jewels for the premiere of “Youth” at the 2015 Cannes Film Festival.

Karlie Kloss strikes a pose on the red carpet for the “Youth” premiere at the 2015 Cannes Film Festival.

The reverse of Karlie Kloss’ dress for the “Youth” premiere at the 2015 Cannes Film Festival.

Another look at Jane Fonda’s Schiaparelli Haute Couture dress, which she wore to the “Youth” premiere at the 2015 Cannes Film Festival.

Shown up close are the Cartier jewels that actress Jane Fonda wore to the “Youth” premiere at the 2015 Cannes Film Festival.

Cate Blanchett, for the premiere of the movie “Sicario”, directed by Denis Villeneuve, chose to wear a Giorgio Armani Privé dress with plunging neckline, made of black silk cady decorated with bamboo leaf patterned embroidery with tonal Swarovski crystals.

Poppy Delevingne in a Chanel floral gown and Chopard sapphire necklace at the Chopard G.O.L.D. party on Monday evening in Cannes.

Emily Blunt‎ donned a bespoke Stella McCartney nude silk crepe de chine diamond-embroidered long-sleeve gown with open back at the “Sicario” premiere on Tuesday at the 2015 Cannes International Film Festival.

Another look at Emily Blunt’s gown at the “Sicario” premiere on Tuesday at the 2015 Cannes International Film Festival.

At the “Sicario” photocall, Emily Blunt wore Peter Pilotto’s wool and jacquard “Ludo” dress with eyelets and metal embellishments from the Fall/Winter 2015 collection.

Cate Blanchett wore a voluminous, Tudor-inspired, digitally-printed Giles ball gown to the premiere of “Carol” at the Cannes Film Festival on May 17.

Cate Blanchett, right, and Rooney Mara both chose Alexander McQueen for the May 17 “Carol” photocall during the Cannes Film Festival.

Blanchett is wearing an AW15 laser cut leather jacket, engineered knit top and skirt, while Rooney wearing a Pre AW15 Ivory Broderie Anglaise dress and belt.

Actress and jury member Sienna Miller wears a Sonia Rykiel gown and Bulgari jewels at the “Carol” premiere during the 68th annual Cannes Film Festival.

Actress Jane Fonda wears a form-fitting blue Atelier Versace gown to the premiere of “The Sea of Trees” at the 2015 Cannes Film Festival on May 16.

Diane Kruger in Prada at the Cannes Film Festival premiere of “The Sea of Trees” on May 16.

Diane Kruger wears Prada at the Cannes Film Festival on May 16.

Diane Kruger poses for photographers in a Prada gown at the Cannes Film Festival on May 16.

A closer look at Naomi Watts’ earrings as she poses for photographers May 16 at the Cannes Film Festival.

Natasha Poly in a Michael Kors custom gold metallic fil coupé bias gown and Boucheron serpent necklace for the premiere of “The Sea Of Trees” on May 16.

For “The Sea of Trees” premiere at the Cannes Film Festival on May 16, Naomi Watts chose to wear a Giorgio Armani Privé multi-layer bustier dress in silk gauze, embroidered all over with sequins and crystals.

Emma Stone in an Oscar de la Renta black lace mini-dress for the photo call for “Irrational Man.”

A full look at Emma Stone’s Oscar de la Renta dress.

Salma Hayek on the red carpet in Cannes.

Salma Hayek wears an Alexander McQueen embroidered silk organza bustier gown at the premiere of “Il Racconto Dei Racconti” (Tale of Tales).

Another look at Salma Hayek’s Alexander McQueen gown.

Parker Posey wears a quirky-looking gold turban, dark shades and a shimmering coral midriff-baring dress at the premiere of “Irrational Man.”

Ines de la Fressange wears an antique rose draped silk gown to the premiere of “Irrational Man.”

Cheryl Fernandez-Versini wore a custom Ralph & Russo nude silk crepe column gown with draped sleeves to the premiere of “Irrational Man.”

The reverse of Cheryl Fernandez-Versini’s Ralph & Russo dress.

Emma Stone opted for a Dior haute couture gown with a train for the premiere of “Irrational Man.”

Emma Stone arrives for the premier of “Irrational Man.”

Charlize Theron is in a strapless yellow Dior gown at the Cannes premiere of “Mad Max: Fury Road.”

Another look at Charlize Theron’s gown on the Cannes red carpet.

Naomi Watts in a Ralph Lauren Collection strapless black wool-cashmere floral lace evening dress with tulle overlay at the premiere of “Mad Max: Fury Road” at the 68th annual Cannes Film Festival.

Julianne Moore in a custom Givenchy red velvet and leather single-sleeve gown at the Cannes premiere of “Mad Max: Fury Road.”

At the “Mad Max: Fury Road” premiere, Fan Bingbing wears a dusty gray V-neck tulle gown with smocking detail along billowing sleeves and delicate pastel multi-color feather and crystal bouquets paired with a feather and crystal bouquet headpiece from the spring ’15 Marchesa collection.

Liya Kebede heads to the “Mad Max: Fury Road” premiere in a Proenza Schouler copper textural sequin embroidery asymmetrical top and black chiffon eyelet embroidery skirt from the fall/winter 2015 collection.

The reverse side of Liya Kebede’s dress.

At the premiere of “Mad Max: Fury Road,” French actress Sophie Marceau sports an Alexandre Vauthier haute couture white silk wrap-front shirt dress from the spring/summer 2014 Couture collection.

Detail of Julianne Moore’s earrings.

Another look at Fan Bingbing’s Marchesa gown.

At the opening ceremony of the 2015 Cannes Film Festival, Lupita Nyong’o wore a one-of-a kind Gucci jade-colored chiffon plisse gown with cape detail featuring an embellished floral detail of embroidered crystals and hand-painted pink and blush silk flowers.

Julianne Moore arrived at the opening ceremony in a Giorgio Armani Privè column dress with plunging neckline, made of silk gauze with aqua and black Swarovski embroidery, and featuring a top decorated with feathers.

Another look at Julianne Moore’s dress.

Naomi Watts chose a powder blue, deep neckline, short-sleeved gown with embroidered sequins and pearls and a long feather skirt from the Elie Saab haute couture spring/summer 2015 collection.

A closer look at Naomi Watts’ gown.

At the opening ceremony, actress and jury member Sienna Miller donned a custom-made Lanvin creation by Alber Elbaz — a navy blue and black matte stretch one-shoulder gown with bow at the neckline.

Karlie Kloss chose a crystal mesh jumpsuit with an asymmetrical neckline and white bandeau top from the Atelier Versace fall 2014 collection for the opening ceremony.