Sophie, Duchess of Edinburgh turns the milestone age of 60 on Jan. 20. Here, fashion insiders, including designers of some of the royal's favorite brands, reveal the secrets of her style evolution.

Sophie, the Duchess of Edinburgh, rang in her 60th birthday by posing for an official portrait in a white Proenza Schouler coat paired with a brown turtleneck and wide-leg bright green pants. The elegant yet modern look paired with a bold splash of color–a welcome departure from the conservative power suits she wore in her early royal days–showed just how far Duchess Sophie’s style has come over the years.

Sophie, the Duchess of Edinburgh posed for a new portrait for her 60th birthday, and photographer Christina Ebenezer is sharing an unseen picture.

The duchess is set to celebrate the milestone at home with the Duke of Edinburgh on Monday at her Bagshot Park home.

Sophie, the Duchess of Edinburgh is turning 60 in style. The royal—who marked her milestone birthday on Monday, January 20—released a trio of stunning portraits to commemorate the special occasion over the weekend that seemingly included a subtle sartorial nod to her grand new title.

In a series of candid photographs by Christina Ebenezer, the Duchess of Edinburgh chose a wardrobe of re-wears that hint at her new era of royal life

Sophie, the Duchess of Edinburgh is marking a milestone birthday! She turned 60 on Jan. 20, and friends and former colleagues have been honoring her contribution to the royal family – amid the release of the duchess' stunning new portrait.