One of Hollywood’s most talked-about films had its world premiere in London’s Leicester Square last night as director James Cameron joined the film’s stars Sigourney Weaver, Sam Worthington, Michelle Rodriguez and Zoe Saldana at the star-studded screening.

And while she might play an unglamorous blue alien in the movie ‘Avatar’, Zoe Saldana was anything but when she hit the red carpet last night for the film’s London premiere.

A newcomer to the Hollywood scene, Zoe Saldana owned the blue carpet wearing an absolutely breathtaking RM by Roland Mouret silver mermaid gown. So completely different that anything we’ve seen on the red carpet, Zoe was the vision of perfection in the textured silver gown with structured shoulders, which channeled her alien character.

Saldana paired the futuristic look with a long Neil Lane diamond necklace, which was the perfect accoutrement to the ensemble.

In the film, Saldana’s computer-generated blue alien character Neytiri falls in love with a former U.S. marine Jake Sully, played by Australian actor Sam Worthington, who is left paralyzed after a conflict on Earth.

Zoe’s facial expressions, speech and movements were used to create a computer-generated image of her on-screen alter-ego, the blue alien Neytiri.

‘Avatar‘ was first conceived by James Cameron 15 years ago – shortly before he made his biggest blockbuster ‘Titanic,’ but was only realized when technology caught up with his vision. Arriving on the red carpet he said: ‘It’s a great feeling of satisfaction.

Meanwhile, on the other side of the pond, Roland Mouret was celebrating the L.A. launch of his exclusive Rainbow Collection for Net-a-Porter with a bevy of Hollywood starlets showing off his latest creations.

Demi Moore, Heidi Klum, uber stylist Rachel Zoe, Lily Cole Amber Valletta, Olivia Wilde, photographer Amanda de Cadenet and Devon Aoki were just some of the lovely ladies who attended (and modeled) Roland Mouret’s Rainbow Collection launch for Net-A-Porter held at LA’s Chateau Marmont. Stars were decked out in Mouret’s signature sculptural designs in look-at-me hues like turquoise, fuchsia and orange.

Hot mama Heidi Klum put her shape on show in a lilac thigh-skimming confection from RM by Roland Mouret saying of her new shapely figure, ‘I embrace that I have more curves right now.’

Galaxy dress

Mouret’s skill in garment construction has allowed him to create irresistible and sensual clothing that is embraced by Hollywood heavyweights and the fashion world. In 2006, Mouret introduced his Galaxy dress which was called the “dress of the season” by many. Its ubiquity was such that Vogue magazine would later write that “for weeks you [couldn't] open a newspaper or magazine without seeing another young Hollywood A-lister wearing” it. Since then Roland Mouret has developed a huge celebrity following thanks to his gift of creating sculptural designs that women of all shapes can embrace.

Demi Moore opted for a more classic style in a black single-shoulder RM by Roland Mouret dress worn with peep-toe pumps while Devon Aoki opted for a bold marigold yellow RM by Roland Mouret minidress.