Kate Middleton's St. Patrick's Day Outfit Included a Genius Detail to Support Shamrock Sprig

Shutterstock The Princess of Wales on St. Patrick's Day - March 2023

Kate Middleton loves a style hack!

While the Princess of Wales, 41, was a style surprise in vibrant teal, rather than traditional green, on St. Patrick's Day last week, her discreet fashion hack almost went unnoticed.

Alongside Prince William, Kate joined the Irish Guards for their annual parade in Aldershot on Friday wearing a bespoke look by Catherine Walker & Co. The outfit made headlines for its bright hue and clever elements of military design, but did more than just look the part.

On closer inspection, on the left side of the central button fastenings, a simple loop in the same fabric as the coat dress (and matching dress underneath) was added for the traditional shamrock to be pinned on.

The genius detail not only meant that the fabric of the coat dress wasn't damaged by the weighty pin, but served as a guide for the guard whose job it was to pin it on Kate.

Chris Jackson/Getty Kate Middleton on St Patrick's Day 2023

RELATED: Why Kate Middleton's Unexpected Teal Ensemble Was the Perfect Shade for St. Patrick's Day

It's not the first time the thoughtful touch has been added to one of Princess Kate's outfits. Last year, for the same event, designer Laura Green added a circular piece of fabric to her dark green coat dress, and the detail was later concealed by the shamrock.

According to the British Army, Queen Victoria started the royal tradition of shamrock distribution on St. Patrick's Day in 1900 as formal recognition of the bravery of the Irish Guards during the Boer War.

Samir Hussein/WireImage The Princess of Wales on St. Patrick's Day in 2022

Princess Kate has participated in the annual St. Patrick's Day parade with the 1st Battalion Irish Guards for over a decade, but this year was extra special — her first as the new honorary Colonel of the Irish Guards. King Charles gave his daughter-in-law the new title in December, one that she said in a speech she did "not take lightly."

It's perhaps due to prestigious nature of the event that her style team put especially careful thought into her outfit. It was no coincidence that the central buttons on the outfit were configured to mirror those on the Irish Guards' uniform, arranged in groups of four. Additional military nods in her outfit include the mandarin collar and masculine tailoring, particularly the sharp edges of the shoulders.

RELATED: Kate Middleton Sports Camo to Visit Irish Guards for the First Time Since Becoming Their New Colonel

Karwai Tang/WireImage The Princess of Wales at the St. Patrick's Day parade, March 2023

The green-blue teal also perfectly matched the plumes worn in the bearskin hats of the Guards and features prominently in their regimental badge.

Also known as St. Patrick's blue, it's the color that is historically associated with Ireland (since the 1780's when it was adopted as the Anglo-Irish Order of St. Patrick) rather than the more modern interpretation of green. The felt hat with delicate crinoline detail from Jane Taylor also appeared to be a nod to the plumes of the historic bearskin hats.

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!

Andrew Matthews/PA Images via Getty Kate Middleton, the Princess of Wales on St Patrick's Day 2023

Kate completed the look with meaningful accessories. In addition to sporting diamond and emerald earrings, giving her outfit a touch of classic green, she sported a special shamrock brooch featuring a small emerald in the center.

The brooch belongs to the Irish Guards and is loaned to the royal women who are associated with the regiment, according to The Court Jeweller. Before Kate, it was worn by Princess Anne and the Queen Mother.