Cerulean blue is the trending colour Kate Middleton loves - and her pastel midi dress is the perfect staple for sunny spring

The recent warm weather and sunshine has got me excited for summer already and, as ever, the Princess of Wales is a source of inspiration. A lot of her go-to summer dresses could also easily have a place in a spring wardrobe and if I had to pick one of my favourites it would surely have to be Kate’s blue floral frock from 2023.

She’s only been spotted in it this one time but given how much she loves re-wearing things, perhaps this means she tends to wear it when she’s not out in public. Instead, it could be a go-to dress for her daily life and it’s by one of the best British clothing brands, Beulah London.

The Princess stepped out in it when she attended the Outsourcing Inc. Royal Polo Cup and this gorgeous cerulean blue colour is a huge spring/summer fashion colour trend for 2026. Once again, Kate was ahead of the curve and what better way to wear the shade than this?

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Cerulean is derived from the Latin word for ‘sky’ and Kate’s Sonia Blouson Sleeve dress was definitely a true sky-blue tone. She has a lot of different clothing items in this colour besides the frock, from blazers to coats, though this wasn't totally blue. It was covered all over with a delicate, white floral print and fell to ankle-length.

A matching belt cinched it in at the waist and it was made from silk crepe de chine. Even if you’re not someone who usually follows colour trends, this blue is worth considering. It’s such a wearable pastel and adds a pop of colour to an outfit in a more subtle way.

As the Princess proved, it complements both white and beige tones, and I think tan would also work exceptionally well with cerulean blue. It’s not so different from light-wash denim and we all know how easy it is to style jeans with virtually any colour.

With something like a dress or a jumpsuit that is pretty much your entire outfit, though, keeping everything else pared back will allow them to take centre stage. Tailored trousers and jackets are other alternatives that you can often find in this kind of pastel blue, especially as we edge closer to wedding season.

A cerulean blue suit would be fabulous for a special event and you could also dress the separates down with casual clothing staples.

Kate went for a pair of classic nude-beige slingback heels by Camilla Elphick for the polo, forgoing her favourite wedges. Her only other accessories on that sunny July day were a matching sky-blue Mulberry handbag and a pair of dark sunglasses. Everything looked put-together and in balance.

White trainers would also look great with a frock like hers, though it makes sense she’d want to go for something smarter. Although this wasn’t a royal engagement, the proceeds from the cup go towards charities close to her and Prince William’s hearts and he competed personally.

The Prince of Wales’s team ended up winning and we got to see her give him a congratulatory hug. It was an opportunity to see them in public when they’re totally relaxed and not undertaking royal duties and this is why I think Kate’s dress might well be something she wears as a primarily non-work outfit.