Dutch Royals Celebrate King's Day (King Willem-Alexander's Birthday!) with a Fun Fashion Swap

Happy King's Day — or "Koningsdag," if you want to say it like the Dutch!

To celebrate King Willem-Alexander of the Netherlands' 55th birthday on Tuesday, the entire country was ready to party — after all, this year's festivities marked the first time since 2019 that the day was able to be marked without COVID-19 restrictions.

King Willem-Alexander, Queen Maxima and their three daughters — Princess Catharina-Amalia, 18, Princess Alexia, 16, and Princess Ariane, 15 — celebrated the day in the city of Maastricht. But before stepping out for the day, they got together for a family photo shared on the royal family's Instagram page.

In the snap, it appears that Queen Maxima and her two eldest daughters made sure to coordinate their outfits via their purses. Queen Maxima carried a beige handbag that matches Princess Catharina-Amalia's blazer and matching trousers, Princess Catharina-Amalia chose a green purse that matches Princess Alexia's outfit and Princess Alexis opted for a pink purse just like her mother's dress!

The family's day in Maastricht included King Willem-Alexander and Queen Maxima, 50, toasting with orange bitters, appropriately as orange is the color of the royal family (which has the name the House of Oranje) and the country's national color.

The royals also posed for selfies with members of the public, most of them also decked out in their best orange outfits.

King Willem-Alexander, Queen Maxima and their daughters even joined a dance group in jumping around and waving their arms to an upbeat song.

In addition to parties and drinking, people are allowed to sell things on the street without requiring a permit on King's Day, according to Holland.com.

"Flea ("free") markets are held in parks and streets, with many people offering their unwanted possessions, music or other entertainment for sale. In Utrecht, the flea markets even start the night before King's Day," according to the website.

King's Day changes depending on the ruling monarch's birthday (although a winter-born monarch may opt for a warmer month to celebrate) — and it is also known as Queen's Day, should the monarch be a woman, as it was before Willem-Alexander's mother abdicated the throne.

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Last week, King Willem-Alexander joined Prince Harry at the final day of the Invictus Games, which were hosted in The Hague. Together, they watched the wheelchair basketball finals between the Netherlands and the U.S.