Kate had made a quick outfit change into an Erdem number. The electric blue Jacquenta dress featured floral lace applique across the shoulders and sleeves and a split skirt.
She accessorised with nude patent platform shoes and a matching mock-croc clutch bag.
It was the second time she'd worn a design by the Canadian-born British creator. On arrival in Ottawa last week, the Duchess was in a lacy number of his that also won plaudits.
At the drop in centre the couple managed to win themselves another fan - a punk with blue and green hair named Pierre.
A circus skills student, he was thrilled when the Duke described his juggling as “awesome”.
The 24-year-old, who was living on the streets before the centre helped him find a home, was eager to praise the newlyweds, saying it was “special to meet them, a privilege”.
They were shown around the centre by Steven, 21, who wore a bullet through his earlobe.
Competitive Prince William took Steven on in a game of table football, shouting “Come on the claret and blue”, in a reference to Aston Villa, the football team he supports.
More on William and Kate's debut tour
Watch: Prince William takes George to meet his sister
It's a little princess!