Royals Kate Middleton Recycled Her Famous L.A. Look from a Decade Ago — Compare the Then-and-Now Photos! The royal mom also pulled accessories out of her jewelry box for the Earthshot green carpet By Stephanie Petit Stephanie Petit Stephanie Petit is a Royals Writer and Reporter at PEOPLE. People Editorial Guidelines Published on October 18, 2021 11:03 AM Share Tweet Pin Email Kate Middleton and Prince William understood the assignment. The couple hit the green carpet on Sunday for the inaugural Earthshot Prize awards, an environmental initiative launched by Prince William. In keeping with the earth-friendly theme, guests were asked not to purchase new frocks or suits for the evening. Kate, 39, chose a lilac gown by her wedding dress designer Alexander McQueen. She previously wore the ensemble more than 10 years ago, when the couple attended a BAFTA event in Los Angeles during their 2011 visit to the U.S. However, she gave the dress a slight update, replacing the original belt with a bead-studded accessory from Jenny Packham's 2018 bridal collection. Kate Middleton. Samir Hussein/WireImage; Julian Parker/UK Press via Getty Images The royal mom also pulled accessories out of her jewelry box for the Earthshot event, recycling Kiki McDonough earrings that she previously wore to her sister Pippa Middleton's wedding in May 2017. Queen of Royal Rewears! See All of Kate Middleton's Best Recycled Outfits Prince William. Samir Hussein/WireImage; Dominic Lipinski - Pool/Getty Images Kate's outfit choice may have also hinted at the location for next year's Earthshot Prize ceremony, which William announced will be in the United States. Prince William, 39, also pulled a previously worn piece out of his closet — an appropriately green velvet suit that he previously debuted in 2019 while attending the Centrepoint homelessness charity's 50th anniversary gala. Instead of the white shirt and bow tie he wore two years ago, William paired the suit with a black turtleneck for Sunday's Earthshot event. Prince William and Kate Middleton at the 2021 Earthshot Prize Awards. Joe Maher/Getty Presenter Emma Thompson said she came in the outfit she wore when she last saw Prince William — her suit and the badge that signifies her damehood. "On our little notes they said 'Please do not buy anything new for this.' Can you imagine? The relief! So I got my dame suit that I wore when I went to the palace," she shared. Meanwhile, Emma Watson opted for an upcycled look created using secondhand bridal dresses by London-based designer Harris Reed. Can't get enough of PEOPLE's Royals coverage? Sign up for our free Royals newsletter to get the latest updates on Kate Middleton, Meghan Markle and more! Kate is known for her royal rewears, but her lilac gown marks the second time in a week that she's worn a piece that's been in her closet for years. Kate and William joined school children at a London park on Wednesday for a Generation Earthshot event to discuss ideas to help repair the planet, where she sported a green jacket also worn during the couple's 2014 tour of New Zealand. Bev Hayes, a well-wisher who met Kate during the Cambridge, New Zealand visit seven years ago, previously said, "I complimented her on her green dress. She said she liked it but Prince William thought it was a bit bright."