Earlier in 2023, the Princess of Wales took over the Prince's role as Regimental Colonel of the Irish Guards. Green, then, is a nod to her position regarding the infantry combat brigade that guards the royal family and also specializes in scouting, reconnaissance, and sniper deployments.

In March 2023, Princess Catherine visited the Irish Guards, formed in 1900 and known for their charm, at their St. Patrick's Day Parade, as reported by the official royal website. Following tradition, she presented sprigs of shamrock to the officers and guardsmen, and, speaking to the assembled soldiers, expressed pride and honor to be named their Colonel. "I am here to listen to you, to support you, and to champion you in all you do – this is a responsibility I do not take lightly." 

Admirers of Princess Catherine do not doubt that she will fulfill her duty to the guards, who can be deployed anytime, anywhere worldwide, to aid allied nations during an early stage of a potential conflict. Her choice of green, then, is a clear nod to this British Army unit.