Why did Queen Elizabeth II choose a blue outfit for her latest official portrait?

In this original new picture, the sovereign chose to wear a sky-blue outfit, a color that was almost certainly not chosen at random.

While Kate Middleton's outfits may be frequently scrutinized, she is not -- and far from it -- the royal family's first fashionista. Queen Elizabeth II's dresses, coats and hats are closely studied at each of her official outings, and sometimes even get bookmakers in a frenzy.

Meticulously crafted and always loaded with symbolism, the Queen's style of dress inevitably conveys messages -- whatever they may be -- and the color choices for her outfits are never left to chance.

So why might the Queen have opted for a light blue ensemble in her new official portrait by photographer Ranald Mackechnie?

Simple, understated, discreet

For this portrait, which celebrates seven decades of the Queen's reign, it would have been out of the question to wear a color that would contrast with the sobriety and grandeur of the place where the picture was taken, Windsor Castle. In fact, the Queen has rarely chosen bold hues for her previous portraits, most often preferring discreet colors.

The same, however, does not apply to her various outings when, on the contrary, the Queen prefers very bright, colorful clothing. This choice supposedly helps the public to spot her quickly and easily during official events, suggests Robert Hardman in his book, "Our Queen."

For this new portrait, there's no need for Her Majesty to get herself noticed, since she is -- of course -- the central subject of this picture with its formal, official air. A brighter color would have drawn attention to her outfit, more than her face, which is in the center of the picture.

With a candid look, and a slight smile on her lips, this is above all where the camera lens was focused when taking this latest portrait.

Wisdom, serenity and confidence

Often said to be the favorite color of Europeans or, more widely, of Westerners, beyond questions of gender or social status, blue brings people together, it unites consensus, and it was therefore sure to please the subjects of Queen Elizabeth II.

But more than that, the color is not usually associated with a negative symbolism, and is even said to be synonymous with serenity -- echoing sea and sky. It is also strongly associated with wisdom. What better way to celebrate 70 years on the throne?

If it is frequently associated with power, blue is more often a symbol of peace. It is no coincidence that many associations and organizations, such as Unicef, have chosen the shade as their signature. Finally, it is a color that inspires confidence, safety and loyalty.

A strong choice for "the first Monarch in British history to celebrate a Platinum Jubilee," as the royal family emphasized when unveiling the new portrait on Twitter.