Prince George was snapped by his mum for his ninth birthday and the colour of his polo shirt shows a “sense of duty”, reportedly said a psychologist.
Each year the Duchess of Cambridge has published photos she has taken of her three children.
Last year George was pictured wearing a striped polo on top of a Land Rover Defender in a touching tribute to his late great-grandfather Prince Philip.
And the latest photo shows George beaming in a blue top ahead of his birthday on July 22.
It has led to speculation over what is the meaning behind the light blue polo shirt that was taken on a sunny day and he appears to be on a beach - which could be in Norfolk where the Cambridge’s have a residence and often spend their summer holidays.
The colour blue is common historically for the Royal Family and behavioural colour psychologist and author of The Little Book of Colour, Karen Haller, believes the choice for George is designed to show he is “committed”.
The Royal Family are often seen wearing blue and its association also with art, military and business is part of the reason why they like to use it.
The Duke and Duchess of Cambridge are thought to dress their children in blue as it symbolises their cohesion as a family in the public eye.
"Wearing the same hue when the Cambridges are showing they are coming together as a family represents themselves as a cohesive unit," said Ms Haller, reported the Express.
"When it comes to colour psychology darker blues communicates you are in a position of authority, trustworthy, reliable and can be depended on.
"You have a sense of duty and take that seriously with committed focus. There is also an adverse side to blue. That is you can come across as aloof and distant.
"And they don’t want to inadvertently create the feeling that they are unapproachable."
The Duchess of Cambridge is known to be a keen photographer and took the latest birthday snap of George.
Kate is also patron of the Royal Photographic Society and releases pictures on special family occasions such as birthdays.
The Duchess has said how her own children sometimes ask her to put her camera down.
During her Hold Still photography contest, Kate said about Prince George, Princess Charlotte and Prince Louis: "Everyone's like, 'mummy, please stop taking photographs'."