Rihanna rocking the Pope's hat and more holy headgear at the #METGala2018

From saints to sinners, guests took to heart the 2018 theme of "Heavenly Bodies: Fashion and the Catholic Imagination" at the Metropolitan Museum of Art's Costume Institute ball.

Although some commentators had feared the Catholic theme might yield the most controversial Met Gala ever, most of the actors, models and music stars stayed on the right side of propriety in colors of red, white, gold and black.

Celebs showed up in their Sunday's best and the eye-catching headgear they wore did not go unnoticed:

The invitation-only Met Gala is a fundraising benefit for the Metropolitan Museum of Art, and also marks the opening of the Costume Institute’s annual fashion exhibition.

The 2018 exhibit, which like the Met Gala is entitled “Heavenly Bodies: Fashion and the Catholic Imagination,” shows how Catholicism has influenced fashion and designers through the decades and features more than 50 vestments and other religious items direct from the Vatican. — with a report from Reuters / AT, GMA News