Catherine, Princess of Wales attends the 2023 St. Patrick’s Day Parade at Mons Barracks on March 17, 2023 in Aldershot, England. (Photo by UK Press Pool/UK Press via Getty Images )

Kate Middleton is celebrating her first St. Patrick’s Day as Colonel of the Irish Guards and took part in the age-old custom of presenting them with shamrocks. The Princess of Wales joined her husband Prince William and the 1st Battalion Irish Guards at the annual parade in Aldershot, England. Instead of sporting Kelly green, she chose a monochromatic teal ensemble.

Middleton looked appropriately regal in a bespoke Catherine Walker tailored coatdress with eight covered buttons, a high collar and strong, angular shoulders featuring two razor sharp pleats on either side, extending from the neckline.

Catherine, Princess of Wales attends the 2023 St. Patrick’s Day Parade at Mons Barracks on March 17, 2023 in Aldershot, England. (Photo by UK Press Pool/UK Press via Getty Images)

The royal teamed her look with matching Gianvito Rossi suede pumps and an extravagant asymmetrical Jane Taylor London fascinator topped with pleated tulle trim. Middleton adding a touch a bling to her festive outfit with emerald drop earrings with diamond accents, and the historic gold Cartier Irish Guards Shamrock Brooch to her coat with a tiny green gemstone at its core.

Catherine, Princess of Wales smiles during their arrival at the St. Patrick’s Day Parade at Mons Barracks on March 17, 2023 in Aldershot, England. Catherine, Princess of Wales attends the parade for the first time as Colonel of the Regiment succeeding The Prince of Wales, the outgoing Colonel. (Photo by Chris Jackson – WPA Pool/Getty Images)

The brooch is believed to have been created in 2000 and owned by the Irish Guards. The piece is loaned to royal ladies associated with the regiment, per The Court Jeweller. Previously, the pin has been adorned by Princess Anne and the Queen Mother. Middleton, however, has worn it exclusively since 2011.

Middleton passed out shamrocks to attendees, including their adorable mascot – the Irish Wolf Hound named Turlough Mór (also known as Seamus). The Princess added a large spring of the greenery to her own ensemble, pinning it above the Cartier brooch.

Catherine, Princess of Wales and Prince William, Prince of Wales attend the 2023 St. Patrick’s Day Parade at Mons Barracks on March 17, 2023 in Aldershot, England. (Photo by UK Press Pool/UK Press via Getty Images)

Ordinarily, Middleton tends to opt for a rich emerald or forest green ensemble for the annual St. Patrick’s festivities. 2015 was the only exception, when the royal swapped out her usual green outfit for a muted gray look — which was reportedly the more comfortable option as the Princess was heavily pregnant with Princess Charlotte. While this year’s teal ensemble remains in the color family, it remains an unexpected twist.