Kate Middleton sends sales of yellow dresses soaring following the birth of her daughter

The Duchess of Cambridge's appearance at the Lindo Wing in a Jenny Packham dress has inspired shoppers to invest in yellow clothes.

Kate Middleton's immaculate appearance following the birth of her daughter outside the Lindo Wing at the weekend has not just been a hot topic of conversation, but also an inspiration for shopping.

The Duchess of Cambridge opted to wear a yellow buttercup Jenny Packham dress to present her new daughter Princess Charlotte Elizabeth Diana to the world, teamed with a pair of her signature nude heels.

The result has been a 58% increase in sales of yellow dresses, reported by online shopping auction site Ebay.co.uk. And a staggering 94% rise in the sale of nude shoes.

The 'Kate effect' has been much documented, with almost anything the Duchess wears enjoying an instant sell-out and spawning a huge array of copy-cat items.

Newsweek reported in 2012 that the 'Kate effect' was estimated to be worth £1 billion to the British fashion industry.

Prince William and Kate the Duchess of Cambridge hold the Prince of Cambridge outside the Lindo Wing of St. Mary's Hospital, where the Duchess gave birth on Monday (AP)

The Duchess' dress choice following the birth of Prince George had a similar effect on shoppers with her blue polka dot Jenny Packham gown spurring sales of similar dresses across the high street.

Prince William, Duke of Cambridge with his son, Prince George at the Lindo Wing (EPA)

But the Duchess isn't the only fashion icon in her family, Prince George's appearance outside the hospital in a blue outfit has led to a 128% increase in the sales of blue cardigans.