Princess Kate debuts a 'holiday hair' transformation - and it went under the radar

This would make sense as the Wales family reportedly headed to the Caribbean island of Mustique for the February half term, according to the Mail on Sunday.

Sun exposure often lightens the hair due to the sun's ultraviolet rays changing its natural pigment. It kind of zaps the hair of its regular colour and makes it appear lighter. Kate also looked a little tanned in Cardiff, which was post-holiday.

At the start of January, Kate turned 43 and released a stunning birthday portrait in celebration. Taken by Matt Porteous, it showed the super chic Princess, sporting a classic outfit, consisting of skinny jeans, a white shirt, a black blazer and a statement scarf.

Fans were quick to notice that her famous brunette mane looked longer and in better condition than ever.

Professional hairstylist Tom Pike confirmed the change in her tresses, telling HELLO!:

"Essentially, Kate has upgraded the style known as the 'Hollywood wave'. To achieve this, you would use either a smoothing cream or a nice blow-dry spray. Blow dry your hair smooth, then using a large barrel wand, twist the hair around the tool, taking slightly thicker sections as you work. Once this is done, gently brush it out."

Tom, who counts Lily James as one of his celebrity clients, added: "The way that Kate's done it is slightly differently; she's parted her hair at the back and then pushed it forward, so it looks like you've got that real, I call it a 'royal wave', but it just looks like you've got that real deep wave in the hair. It's beautiful."