Prince William’s blue suit and black tie combination is something he’s worn for funerals in the past, including the November 2023 services for Manchester United legend Sir Bobby Charlton.

However, regardless of Vatican dress code, Trump was not the only funeral attendee who did not wear a black suit. Another notable exception was the U.K.'s Prince William, who wore a dark navy suit.

And Mr. Trump owns a dark suit — he wore one to former President Jimmy Carter’s funeral in January. But in this case, black might not have served his purposes.

The royal expert added that since Diana’s favorite suit for a man was navy both of her sons wore dark blue suits in 2021 when they unveiled her statue in the Sunken garden at Kensington Palace.

Historian Ardis Parshall listed 1916 instructions on missionary clothing as being “a good black suit or blue suit, a good overcoat and Derby hat” and “white or light-colored shirts and black ...