Kate Middleton wore a teal coat dress for the St Patrick's Day event as the new Honorary Colonel.

Her outfit perfectly matched the 1st Battalion of the Irish Guards.

Middleton's teal outfit shows her dedication to her role as the next Queen-in-making.

Blue is a symbolic color of Ireland and is frequently worn by the royals.

The plums of a darker blue color matched the mantle and sash of the Order of St. Patrick.

The royals wear blue to display a strong sense of unity and togetherness.

Behavioral color psychologists have shared their insights on the royal family's color choices.

The Little Book of Color author explained the royals' color choice as representing themselves as a cohesive unit.

Kate Middleton's attire garnered attention and admiration from onlookers at the event.