Queen Elizabeth II was born nearly a century ago, but she's still in style today.

The British monarch is always very well-dressed, and there's a particular trend noticeable in her outfits: colour. Whether in bright orange, purple or in pink from head to toe — the Queen is always colourful.

Queen Elizabeth's royal fashion doesn't include one colour

But there is one colour we'll probably never see the Queen wear. Robert Hardman, a royal biographer, said the Queen wears bold colours to stand out at royal events. A simple colour like beige would therefore not be an option for her.

Queen Elizabeth II and Prince Philip

In his book Our Queen, Hardman writes: "My favourite remark [the Queen] ever said was, 'I can never wear beige because nobody will know who I am.'" For this reason, Queen Elizabeth only wears the colour when required to.

Why the Queen wears bright colours at engagements 

For public events, bright colours are a must — the more visible, the better. The journalist Sali Hughes describes the style of the Queen in her book Our Rainbow Queen.  

She "won't wear green to grassy venues, nor dark colours against dark upholstery," writes Hughes. However, if she wants to stand out and it fits the respective event, she is very happy to sport a green outfit.

The Queen celebrated her 90th birthday: Her great-grandchildren Prince George and Princess Charlotte are also there

For example, Queen Elizabeth II wore lime green to celebrate her 90th birthday in 2016. The remaining members of the Royal Family, however, wear muted colours to respect the Queen and not upstage her.

For more on the Queen's fashion, you can click here to see her most beautiful hats.