On May 28, 2016, the small Andalusian town of Íllora, in the province of Granada, became the centre of attention for a few hours. Businessman and philanthropist Alejandro Santo Domingo, of Colombian descent and raised in New York, married Lady Charlotte Wellesley, daughter of the Duke and Duchess of Wellington. The ceremony was held in the church of "Nuestra Señora de la Encarnación", and the celebration continued at "La Torre", the Andalusian estate of the bride's family.

The guest list looked like a cross-section of the European elite: King Juan Carlos, today's British Queen Camilla, then Duchess of Cornwall, supermodel Eva Herzigová, singer James Blunt with his wife Sofia Wellesley. Andrea Casiraghi and Tatiana Santo Domingo were there too. For her the wedding was also a family affair, as the groom is her uncle, even though there are only about six years between them.

Ten years later, fashion chroniclers still keep coming back to one outfit from that wedding - hers. Caroline of Monaco's daughter-in-law has never followed trends literally. Her style has always moved between bohemian inspiration, special pieces and relaxed combinations, with a hippie touch that suited her free, creative spirit. At that wedding she stayed true to herself, but made a choice that was much rarer among female guests back then: she came in black.

She wore a long silk chiffon skirt by Giambattista Valli, with a black base and a delicate floral print, paired with a black short-sleeved T-shirt, cut slightly loose, with lace on the sleeves. Hair worn down. And the only accent of colour - red strappy sandals, matching the lipstick. Nothing looked calculated, and yet everything fit together.

Why was it bold? For a long time protocol avoided black at weddings because of its link to mourning. Today it is common at afternoon and evening weddings. "It became popular because of its timeless elegance and its constant presence in haute couture. Today it is seen as a chic and modern choice," says designer Juan Avellaneda. Carmen de la Puerta, founder of the brand "Vogana", goes even further: "It wasn't that long ago that brides got married in black. Queen Victoria was one of the first to change the colour on such an important day, in 1840, when she married in white. Personally it doesn't bother me at all - on the contrary, I think it's extremely elegant."

Avellaneda has another piece of advice that Tatiana Santo Domingo was already applying back in 2016: liven up black with colourful, metallic or shiny accessories. She did it with one pair of red sandals.

Would black at a wedding in the Balkans get past the aunts at the family table without a comment - or is that protocol stricter than the aristocracy's? Ten years on, her choice is a reminder that staying true to your style, even when it means breaking an old rule, rarely looks bad with time.