Kate Middleton, Duchess of Cambridge, has been getting along very well with Queen Elizabeth II since being married to Prince William for nearly a decade. As Prince William is being groomed for his future, Kate has also adjusted to her role as well.

Duchess Kate confidently pulled off a matching outfit with the Queen during her birthday celebrations. She donned a purple coat, as did Her Majesty. It would appear that Kate is more comfortable with her relationship with the Queen now, and the British monarch likewise with her.

Stepping out in twinning outfits, it is believed that Kate has now become the favorite of Queen Elizabeth. While Meghan Markle had returned and is sometimes photographed with the Queen, too, Meg has never had the privilege to match her outfits with the Queen's as Kate now has.

Kate Takes a Spin on Queen's Look

Kate went twinning with the Queen in a muted plum-colored coat. She paired it with a royal blue fedora hat. Blue is known to be the Queen's favorite color. The Queen also wore purple, opting for a more vibrant hue as she is known for her style.

Purple bears huge significance in royalty for many centuries. The Queen often favors this color and even Princess Anne as well as Camilla, Duchess of Cornwall, also wear deep shades of purple.

In history, only rulers could afford wearing purple garments. The color became closely associated with royalty, wealth and power. The elite would be known for the cost of dye of their purple garments.

During the time of Queen Elizabeth I, the Tudor ruler had banned close Royal family members from wearing the color. Only she was able to wear it.

Decoding Their Outfits

As is tradition, Prince William and Kate joined Her Majesty to church in Sandringham on Sunday. This showed clear support for the British monarch. Even Kate's purple coat and blue hat hinted at her dedication to the monarchy and to her future role.

With Prince Charles taking over soon, Prince William is being groomed for his future role more intensely. Kate, who will be future Queen consort is also groomed to be a solid support for her husband. Similarly, the Cambridge children will also be trained for this purpose.

Kate opted to wear similar hats with the Queen. Instead of fascinators she usually wears, she chose a Hicks & Brow feathered fedora to keep it young and daring. Kate wore a purple Roksanda coat that retailed for £2,600. The coat is no longer available for purchase.

The Duke and Duchess of Cambridge walked to St. Mary Magdalene church, which is near to the Sandringham Estate, on Sunday morning, where they accompanied Queen Elizabeth to the service. #BestShots #katemiddleton #katemiddletonstory #DuchessofCambridge #princewilliam #dukeofcambridge #love #style #princesscharlotte #Princegeorge #weadmirekatemiddleton #beauty #instaeffects #bestoftheday #like4like #likeforlike #tagsforlikes #instagood #instamood #instadaily #photooftheday #flawless #princelouis #pretty #handsome #lifestyle #me #amazing #followme #follow4follow

278 Likes, 3 Comments - Fanpage (@hrhduchessofcambridge_) on Instagram: "The Duke and Duchess of Cambridge walked to St. Mary Magdalene church, which is near to the..."

Birthday Celebrations

The visit of Kate, Prince William and the Queen to the church was due to the celebration of the Duchess of Cambridge's 38th birthday. Kate's actual birthday is Jan. 9, but she celebrated it earlier with friends and family over the weekend.

The royals had a birthday party for Kate after church. The Duchess' parents Michael and Carol Middleton were there, as well as their close friends, Rose Hanbury and Tom van Straubenzee.

It has been the Cambridge family tradition to entertain their friends in their Norfolk home at the beginning of every year, before Kate's birthday. The Cambridges have since returned to London as their children, George and Charlotte are set to return to school.

READ MORE: Kate Middleton ALMOST Became ANOTHER Camilla -- Here's Why