Hollywood's biggest stars are turning on the style as they walk the red carpet for the glittering ceremony in Los Angeles on Sunday. They include Clueless star Alicia Silverstone (above), who looks a total Betty in Christian Siriano with long black opera gloves, after appearing in best picture nominee Bugonia. Hamnet author Maggie O'Farrell, who is nominated for co-writing the screenplay for the film adaptation, opted for a bubblegum pink gown with black lace gloves and mesh fascinator hat. Hudson Williams may not have been nominated at the Oscars, but he has been one of the most notable breakthrough actors of the past year, thanks to his role in TV series Heated Rivalry - the viral hit about two ice hockey players who fall in love. Songwriter Diane Warren, who is nominated for best original song and is hoping for 17th time lucky at the Oscars, wore an elegant satin suit topped off with a black neck bow. Amelia Dimoldenberg, who has returned to the Academy Awards as red carpet reporter and social media ambassador for the third year in a row, wore a sculptural black Ralph Lauren column gown, Jimmy Choo shoes and Bvlgari jewelry.