The Secret Detail in Kate & Will’s Anniversary Pics That We Nearly Missed

We can’t believe that Prince William and Kate Middleton officially tied the knot ten years ago today. And while we were so excited to see the couple’s new anniversary portraits, we almost missed a major detail.

On Wednesday, the Duke and Duchess of Cambridge shared two never-before-seen photos on their official Instagram account (@kensingtonroyal) ahead of their tenth wedding anniversary today.

In the first photo, William and Middleton are sitting on a log in a grassy field, candidly looking off in the distance while holding hands. The second photo—taken during the same shoot—shows the duo standing in a courtyard. The captions read, “10 years” and “Taken this week ahead of The Duke and Duchess’ 10th wedding anniversary.”

Although we love to see these rare moments of PDA caught on camera, it was their matching blue ensembles that really caught our attention. In the images, Middleton is wearing a long sleeve wrap dress while William has opted for a classic navy-blue look, consisting of trousers, a sweater and a button-down shirt.

The secret detail we almost missed? The color blue has special meaning for the duke and duchess. In fact, it’s symbolic of their marriage and wedding considering Middleton’s engagement ring—which once belonged to Princess Diana—features a large blue sapphire surrounded by diamonds. The ring was also prominently featured on the mother-of-three’s hand in both of the portraits. In addition, on their wedding day, couples are also supposed to wear something old, something new, something borrowed, and something blue.

Not to mention, the color is symbolic of this difficult and trying year. The couple has matched in blue on more than one occasion this year—for a surprise TV appearance and for a hospital visit—to pay tribute to the U.K.’s NHS (National Health Service), since blue is considered the organization’s official color.

Blue is definitely a good look on these two.

Stay up-to-date on every breaking royal family story by subscribing here.