From Penelope Cruz's stunning red to Gwyneth Paltrow in subdued silver, all eyes were on the fashion choices Sunday as Hollywood's A-listers hit the Oscars red carpet.

And as for the famously quirky British actress Helena Bonham Carter - shock! - she wore a surprisingly normal-looking black dress.

"I thought it would be nice to celebrate film not fashion... I've got a bit of a complex about my bum so thought I'd make it even bigger," she joked, shortly before the 83rd Academy Awards show got under way.

Bonham Carter, nominated for best supporting actress in Oscars frontrunner "The King's Speech," is known for her unpredictable dress sense and had forecast whatever she wore could be "catastrophic."

At the Golden Globes she wore one red shoe and one green, but on Sunday she kept her vow to wear same-colored footwear, below a Gothic-looking black dress described as "something I got together with costume designer Colleen Atwood." Apart from a large bustle, it was supremely conservative compared to outfits she has stunned fashion-watchers with in the past.

Natalie Portman, who is tipped to win the best actress prize for her role as a paranoid ballerina in "Black Swan," was in purple Versace, but insisted she felt at home whatever she wears.

"Most girls get so excited to get dressed up," she said, adding that she could equally be happy "at home in sweats with, like, messy hair and no makeup. The biggest luxury of all."

Cruz, arriving on the arm of husband and best actor nominee Javier Bardem, looked typically ravishing in a red number, the same color as last year's best actress Oscar winner Sandra Bullock.

Paltrow, who said she hadn't slept for a week before the show - in which she is expected to sing - was in a classic silver Calvin Klein, while Hillary Swank's dress had a fluffy tail.

Best actress nominee Nicole Kidman was in a white Dior gown, while best supporting actress hopeful Amy Adams looked nervous in a dark blue sparkly L'Wren Scott dress.

Melissa Leo, a best supporting actress nominee for her role in "The Fighter," was transformed from her character's brassy bottle-blonde with soft hair and a big lacy, silvery dress.

Oscars co-host Anne Hathaway was spied arriving resplendent in a red strapless, big-bustled number - the first of no doubt numerous costume changes in store for her during the evening.

Black Swan star Mila Kunis was in revealing lilac cut low across the bust, described as a "lace and chiffon neo-classical number" by designer Randolph Duke.