Princess Charlene of Monaco and Prince Albert II
Charlene, Princess of Monaco kisses the hand of Pope Francis, as her husband Prince Albert II of Monaco looks on prior to a private audience with the pontiff at the Vatican on 18 January, 2016 Getty Images

Princess Charlene of Monaco adhered to protocol during her Vatican state visit. She had an audience with Pope Francis at the Apostolic Palace wearing the so-called "privilege of the white" ensemble.

Princess Charlene, who is visiting Vatican along with her husband Prince Albert II, followed the tradition of Le privilège du blanc, French term for privilege of the white, in which Catholic queens or princesses are allowed to wear a white dress and a white mantilla, a lace or silk veil. Charlene wore a knee-length coat and covered her head with an intricate lace veil.

The 37-year-old princess paired her all-white ensemble with nude stilettos and white gloves. Charlene, known for her subtle style statements, looked regally elegant as she put bold red lipstick to complete her look.

Princess Charlene, who converted to Catholicism in 2011 before marrying Prince Albert II, is one of the seven "privileged" royal ladies in the world to be allowed to wear white during an audience with the pontiff. The dress code for rest of the royal women and head of states is black dress and black mantilla.

With the recent visit, Princess Charlene, a former South African Olympic swimmer, has also become a privileged royal to use the privilege of the white tradition twice. She wore a white dress and white lace mantilla for an audience with Pope Benedict XVI during her visit to the Vatican in January 2013.

The other six royal women who have had the privilege are Queen Sofia of Spain, Queen Paola of Belgium, Grand Duchess Maria Teresa of Luxembourg, Queen Mathilde of Belgium, Queen Letizia of Spain and Princess Marina of Naples.