
There are guidelines provided by Vatican regulations regarding appropriate attire for meeting the pope on particular occasions. However, only a select few royal ladies are able to wear white as a symbol of three particular virtues.
Only seven women worldwide are permitted to wear white when meeting the pope, despite the fact that many people have met him over the years. They are not allowed to do so, though, when they are at papal funerals. What we know about the tradition is as follows.

How the Dress Code for Royal Women Meeting the Pope Changed
In 2009, Camilla, the current Queen Consort, met Pope Benedict XVI while she was still the Duchess of Cornwall. She donned the traditional long-sleeved black dress with a lace mantilla, or veil, to that encounter.

For generations, women had followed this clothing rule when they met His Holiness. But Camilla wore a pale gold dress and coat by Anna Valentine when she met the now-deceased Pope Francis in April 2017.

The Queen Consort apparently disregarded the Vatican’s dress rule by choosing not to wear headgear. Pope Francis, however, welcomed the change, therefore her appearance was not a problem. “Things have become more relaxed over the last few years [sic] there are no hard and fast rules,” a Vatican spokeswoman once.