Reason why Kate Middleton looked different during rare public appearance finally explained

Earlier this month (14 July), Kate Middleton made a rare public appearance at the Wimbledon finals amidst her ongoing cancer treatment.

However, while many fans of the Royal Family were beaming to see the Princess of Wales, 42, out and about - many noticed a key difference in her appearance.

Now, this was Kate's first public appearance in almost a month as she was last seen at Trooping the Colour alongside her husband, Prince William.

Kate, who was joined by her daughter Princess Charlotte, took her seat in the front row of the Royal Box at Centre Court she was greeted with a standing ovation.

She was wearing a £1,295 purple bespoke 'Cecilia' dress in the colour 'lilac' from London fashion designer, Safiyaa, a brand she previously wore at the Royal Variety Performance back in November of last year.

She also paid tribute to her role as patron of the All England Lawn Tennis with the regal colour choice and, after taking over the patronage from Queen Elizabeth back in 2016. The Princess also accessorised her Wimbledon outfit with a bow tie pin, which featured the club's official dark green and purple colours.

Kate Middleton at the Wimbledon finals earlier this month (14 July). (Karwai Tang / Contributor / Getty Images)

However, it was Kate's hair that attracted some attention as she seemingly switched up her 'do for the occasion.

John Frieda's Creative Stylist, Michael Gray, explained to Hello! a little more about the Princess' barnet.

"The Princess of Wales went for a very beautiful, and bold colour with her dress to Wimbledon this year, which flattered not only her skin tone, but made her brunette hair look rich and vibrant," he explained.

The expert continued: "I loved how she went with a fresh and elegant blow-dry that bounced with an underneath bend."

Additionally, Michael pointed out Kate's change in parting as she usually opts for a middle-part.

"With a heavy side parting to create the illusion of more volume on top that's very wearable and simplistic," he added. "Sometimes less is more, and understated with the power of a good bouncy blow-dry.

"Tucking her hair behind the ears for more of a clean look with the neckline of the dress to create a polished finish."

The Princess of Wales opted for a side-part during her public appearance. (Karwai Tang / Contributor / Getty Images)

It also seemed like Kate had highlights too - a subtle switch up from her signature block brunette look.

The mother-of-three has been undergoing treatment for cancer over the last six months after making the announcement back in March.

In the statement, Kate explained: "I wanted to take this opportunity to say thank you, personally, for all the wonderful messages of support and for your understanding whilst I have been recovering from surgery.

"It has been an incredibly tough couple of months for our entire family, but I've had a fantastic medical team who have taken great care of me, for which I am so grateful."

She added: "We hope that you will understand that, as a family, we now need some time, space and privacy while I complete my treatment.

"My work has always brought me a deep sense of joy and I look forward to being back when I am able, but for now I must focus on making a full recovery."