Princess Kate reveals new balayage hair transformation she's kept secretly hidden

The Princess of Wales is officially the queen of Wimbledon, delighting royal fans as she donned a gorgeous green Emilia Wickstead dress with one-shoulder sash detail at the Men's Singles Final on Sunday.

The 44-year-old's beauty look was nothing short of beautiful - she sported lightly defined eye makeup and a slick of berry lip gloss. But did you see her hair? 

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Although she wore her famous locks loose, the royal wore her curls cascading down her back, and they were only visible as she turned round. As you can see in this picture of her on Centre Court, the ends of Kate's Rapunzel locks are blonde, while the rest of her hair appears brown. This modern technique is known as Balayage.

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What is Balayage?

Balayage is a sun-kissed, natural-looking hair colour applied freehand with no foils. It can be totally bespoke as experts can tailor shades and highlights. It's a timeless, low-maintenance way of colouring your hair.

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"Balayage is a great technique for somebody with brown hair wanting to add dimension without a major colour change, and without taking them away from identifying as a brunette," Hannah Gayle, colourist at Hershesons Belgravia, tells HELLO!. "It is a really nice way to add richness, different tones, and essentially make the hair have texture by creating seamless soft pieces that complement brown without feeling like you have had a dip dye, big colour change."

Charlotte and Kate's twinning hair moment

Princess Charlotte was also present at the final and debuted her longest locks yet, wearing her brunette hair in soft, flowing waves that were strikingly similar to her mother's signature style.

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Charlotte's glossy "mermaid hair" fell well below her shoulders in loose curls, with the front sections swept neatly back from her face, a hairstyle Princess Kate has favoured on countless royal engagements over the years.

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The resemblance between mother and daughter was unmistakable as the pair arrived hand in hand, with Kate also wearing her chestnut hair in cascading waves over one shoulder.