Kate Middleton and Meghan Markle
Meghan Markle has changed and starts copying Kate Middleton after becoming an official royal. Pictured: Markle and Middleton attend the first annual Royal Foundation Forum held at Aviva on Feb. 28, 2018 in London. Getty Images/Chris Jackson

Meghan Markle's fashion sense is becoming very similar to Kate Middleton since she has become an official royal.

According to British designer Caroline Castigliano, the royal life has already started changing Markle. She recognized the Firm's protocol and acknowledged how Markle's style has become more similar to the Duchess of Cambridge's.

"The royal family is a firm and the protocol is huge," Castigliano said (via Express). "We're seeing everything about Meghan change. It's very difficult when you're 36 to do this. It's far easier when you're in your early 20s and they can mould and adapt you."

"It's a much bigger job for Meghan. It must be unbelievably difficult that Meghan was a working woman and had her own style. At the moment, she's really dressing like Kate," the designer continued.

The similarities in Middleton and Markle's fashion could be due to the royal mom of three giving tons of advice to the new royal. Also, several sources revealed that Middleton's assistant, Natasha Archer, has been calling in clothes for Prince Harry's wife until she hires her own assistant.

Prior to her royal wedding to the Duke of Sussex, Markle loved wearing black outfits. However, in her recent engagements, she has opted for white or pink dresses.

"If you're going to be seen with the Queen, who wears bright colours, then this neutral palette she's been sticking to is really a measure of respect," Castigliano explained Markle's choice of color. "This much more demure, classic look is absolutely right on key to what she needs to fit in with the family."

For royal etiquette expert William Hanson, it shows that Markle is letting the Queen shine. "The Queen is top of the bill. Meghan is on the bill, not top of the bill," he said.

Meanwhile, according to Karen Haller, an applied color psychology practitioner, wearing pink has "a calming effect on the wearer." She believes that Markle chose this shade for this reason.

"The number of high profile engagements Meghan has had since officially becoming a member of the royal family would no doubt be quite nerve-wracking," Haller explained. "As the softer end of the pink spectrum is physically soothing, it's the perfect antidote to calming those nerves and easing the pulse rate."