Princess Beatrice and her sister Princess Eugenie flew under the radar during the royal family's annual visit to St Mary Magdalene church in Sandringham on Christmas Day.
Flanked by their parents Prince Andrew and Sarah Ferguson, who surprised onlookers by making a public return to the close family fold for the first time in decades, the royal siblings both opted for understated dark coats in shades of navy and black and suede boots. Accompanied by their respective husbands Edoardo Mapelli Mozzi and Jack Brooksbank, Beatrice and Eugenie ensured their mother the Duchess of York took centre stage for the historic moment.
Princess Beatrice, 35, was elegant in a navy belted coat by Maje, paired with the French brand's thigh-high suede boots. She added the 'Mildred' Navy Velvet Headband by JBH Millinery, looking fabulous yet being careful not to outshine her mother in her emerald green Holland Cooper ensemble.
Going even more understated than her sister, Princess Eugenie, 33, wrapped up warm in a dark wool coat that covered her petite frame, teamed with black boots in a similar style to her sister. She completed the look with an Emily-London Headwear headband in cream.
HELLO! spoke to Styled By Sian, aka Sian Clarke, a Personal Stylist and Style Lecturer, about the significance of the York sisters choosing to wear dark tones for their parents' all-important outing.
Revealing that the "cool colour" navy has a "soothing effect" on everyone, Sian explained that Princess Beatrice and Eugenie are likely to have deliberately chosen the dark hue in a bid to blend in.
"Navy is a brilliant choice for both Eugene and Beatrice because it's the most diplomatic colour to wear. Navy is a cool colour and it has a soothing effect on everyone around them," she explained.
"Blue and of course navy are the nation’s favourite colours to wear, it's not going to cause a stir when you walk into a room of people."
It's likely the royal siblings, who are incredibly close, coordinated their outfits ahead of time, making their sombre looks an interesting choice.
Sian continued: "Navy is completely effortless to wear and tells us that the Princesses don't want to draw attention to themselves and are shifting any focus away from them and towards others.
"Their outfits are to help others around them and show support and unison while looking fabulous doing so."
Moreover, the girls left their children at home, ensuring they wouldn't steal the show during the royal outing.
Beatrice is a mother to two-year-old daughter Sienna, whom she shields from the spotlight, but last year she brought her stepson Christopher 'Wolfie' Woolf along to the church service, and Edoardo's little boy proved a royal hit.
Eugenie, meanwhile, is a mother to two-year-old son August and baby Ernest, seven months, who are too young to take part in the procession.
Monday's outing marked a major moment for their mother Duchess Sarah, who was publicly back at the heart of the royal family after joining the King and Queen at church.
It is thought that she was last pictured walking to the service, which is normally reserved for close family, with Queen Elizabeth II in the early 1990s.
She walked beside her ex-husband, the Duke of York. For the second year in a row since being stripped of his military affiliations and royal patronages, Andrew made the walk from Sandringham to church with the other royals.
PHOTOS: 13 sweet times Princesses Eugenie and Beatrice co-ordinated their outfits
Despite finalising their divorce in 1996, Sarah and Prince Andrew have remained good friends and still live together at Royal Lodge in Windsor.
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Love the royals? Check out the latest edition of HELLO!'s A Right Royal Podcast, which details the magic of Christmas and all the fun and festivities at the royal palaces.