Marketplace eBay has reported a 95 per cent rise in sales of yellow dresses after the beautiful brunette was spotted wearing two during her time Down Under.
In what was arguably her best look of the tour, Kate arrived in sunny Sydney wearing a canary yellow dress from designer Roksanda Ilincic.
The striking number won rave reviews from fashionistas, despite her husband Prince William cheekily saying that she looked like "a banana".
Four days later, Kate was pictured in a pastel yellow number on a trip to Taronga Zoo on Easter Sunday.
"The Duchess of Cambridge's wardrobe undeniably affects what's in when it comes to style-hunting on eBay," eBay spokesperson Laura Wilkinson-Rea commented.
"Sales consistently skyrocket after she is photographed in the latest trend."
Kate is not the only famous face to champion the bright colour this Spring/Summer. Susanna Reid wore a lemon frock on Good Morning Britain, while Hollywood star Emma Stone wore a stunning full-length yellow gown to The Amazing Spider-Man 2 premiere in London last week.
After arriving in Brisbane wearing a floral, Lasa Poppy Print dress from LK Bennett, eBay also saw a 94 per cent increase in sales of floral dresses.
And a rise of 88 per cent in sales of green dresses was reported by the website after the Duchess wore a green Erdem coatdress as she arrived at Hamilton airport In New Zealand.