Kate Middleton re-wore a houndstooth Catherine Walker coat previously seen in 2018.

She paired the coat with a Mulberry bag, Aquatalia boots, and diamond earrings.

The coat's vibrant red-and-white color nods to the national colors of both the England and Wales rugby teams.

Kate is the patron of English rugby, while Prince William is the patron of Welsh Rugby Union.

The coat also pays homage to Princess Diana's Moschino skirt suit from 1990.

Princess Diana also re-wore her Moschino blazer during a royal visit to Canada in 1991.

Kate often re-wears old favorites and promotes sustainable fashion.

She is known for her style signature of breathing new life into time-honored fashion pieces.

Kate's fashion diplomacy is similar to Princess Diana's as some fashion rules never go out of style.