The mum-of-three opted for burgundy Jimmy Choo stilettos and a matching clutch, along with earrings also from Erdem.
After making her official return to the royal calendar last week at an event at the Sayers Croft Forest School and Wildlife Garden, she made her first joint appearance with husband Prince William in London today, at the Global Ministerial Mental Health Summit.
The 10 October marks World Mental Health Day, which Kate, William and Harry have shown an interest in for the past couple of years, as part of their Royal Foundation charity.
The event was attended by political figures, experts and policy makers who proceeded to discuss issues such as how to deal with the stigma attached to mental health - a subject very close to the royal's heart.
The duke and duchess were greeted by Health Secretary Matt Hancock
Prince William joked that the painting had been ruined.
The Duke and Duchess viewed a work stream on "Children, Young People and the Next Generation" where they listened to presentations on two case studies of active mental health programmes in Slovenia and the US.
They were met at London's County Hall by Health Secretary Matt Hancock. At the summit, William and Kate visited a stand run by the non-profit organisation United for Global Mental Health, where they heard about the work of Dixon Chibanda, who started an initiative in Zimbabwe teaching elderly women the skills to offer therapy sessions on "friendship benches".
In the lead-up to hosting a Marathon for Mental Health in the United Kingdom in 2017, Prince Harry revealed he'd sought counselling in his early 20's after two years of what he labelled "total chaos" following the death of his mother, Princess Diana. This Friday, she will lead a number of senior royals at Princess Eugenie's lavish wedding at Windsor Castle, where George and Charlotte will feature in the tiny bridal party as pageboy and flowergirl.