She wore a teal-green coat dress by Catherine Walker & Co. with a matching hat, teal suede pumps, and a shamrock-shaped gold and emerald pin.
Kate has been a long-term client of Catherine Walker & Co, favoring its highly structured coat dresses.
She often pays tribute to the occasion with her outfit, often wearing varying shades of patriotic green.
As colonels, William and Kate gave heartfelt remarks to the guards on parade.
Kate praised "Colonel William" and spoke of her enthusiasm and pride for the regiment she will be closely working with.
The couple missed out on the 2021 celebrations because of the COVID pandemic.
Royal fashion expert Christine Ross called Kate's first colonel parade attire "really nice."