The Duke and Duchess of Cambridge attended the Wimbledon Tennis Tournament on July 5, proving once again how in love they are after 11 years of marriage.

They also showed how much confidence they have gained since the beginning of their marriage, when they often seemed nervous and tense.

Darren Stanton, a body language expert, says one indicator of this confidence is that Prince William and Kate Middleton chose the pair's strong attire for the day to match their strict dress code.

"Attending Wimbledon, Prince William wore his trademark suit. Kate, on the other hand, chose a striking blue dress with polka dots - again, true to her power colors of red and blue.

"When she is happy to draw attention to herself and William, she chooses one of her power colors, but when she is not, Kate opts for a neutral outfit to divert attention to more appropriate places."

Stanton also commented on how the couple relates to each other - how incredibly confident they are together and apart.

"Kate and William are a pair who seem to connect on such a deep level that they do not need to show ongoing signs of mutual fondness, such as touch or prolonged eye contact, while out in public to prove that they are deeply connected," says Stanton.

"It's visible even if the couple doesn't indulge in over-the-top PDA, and it's a sign that Kate and William are confident enough to participate in the event not only as a couple but also as individuals."

"For example, when Kate arrived at the venue, she was walking across the bridge, the same level of confidence in her solo as she did when she was sitting alongside William in the stands."