Kate Middleton is flawless in Alexander McQueen for Christmas Day

Kate Middleton was a vision in a bright blue Alexander McQueen coat for the Royal Family's festive celebrations at Sandringham this Christmas Day. 

While Princess Catherine has been a bit of a style icon since she shimmied down the runway in front of Prince William making a DIY sheer dress look effortlessly stylish, the Princess of Wales has levelled up her looks over the past year.

We've seen a shift in the former Duchess of Cambridges' style since she took on the role of Princess of Wales, graduating from pretty A-Line dresses, ditzy prints and sweetheart necklines to her unique brand of power dressing, comprised of clean lights, smart tailoring and pops of bold colour. 

Kate's Christmas Day look is as chic as we imagined it would be, with the Princess of Wales opting for one of her favourite brands—Alexander McQueen—for the focal point of her outfit. The Princess wore an electric blue coat with matching Gianvito Rossi heeled boots and a simple black turtleneck jumper. A striking Juliette millinery hat and some dazzling diamond earrings completed the look.

Princess Catherine's earrings held a special significance, as they previously belonged to her later mother-in-law, Princess Diana. The striking set is crafted from diamonds and sapphires and was a firm favourite with the former Princess of Wales. Kate's hair was worn half up half down, showing off the stunning jewellery.

The whole family attended the festive celebrations at Sandringham, where a special service was held to celebrate Christmas Day. Princess Catherine was seen hand in hand with Princess Charlotte, who wore a similar smart coat in olive green for the occasion.

Endgame author Omid Scobie has previously spoken about how Kate is evolving her style. He told Elle.com when speaking about Princess Catherine's more recent public appearances: "With Kate, we’ve seen these small changes in her character and her approach to work but also just in her demeanour, her confidence, even her appearance. I’m no style expert, particularly with royal style, but we have seen a change even in her working wardrobe.

"We have seen an evolution in her on all fronts, but I also feel that there’s a huge amount of pressure on her moving forward...being kind of the last shiny thing in the royal family. 

"That’s a huge amount of pressure for someone who has, so far, carried out much less engagements than any other member of the royal family. Who, although we don’t ever say it, is technically a part-time working royal.

He continued: "She’s only human, so are the expectations too high for her? It’s going to be very interesting to see how that plays out over the years ahead as the children get older and William and Kate take footsteps closer towards their time as king and queen."