Princess Diana was a style icon in so many ways - and while she often turned heads with her fashion choices, she was also partial to a bold makeup look.
The late royal was in fact fond of electric blue eyeliner, and was often pictured with the bold pop of colour at her waterline - while the rest of her makeup was left soft, peachy and natural.
In Lord Snowdon's stunning 1981 portrait of Diana, the subtle line of blue under her eyes just co-ordinates with her stunning sapphire earrings, making her beautiful eyes stand out even more.
Princess Diana loved her blue eyeliner even before she joined the royal family
And an archive face chart from one of the Princess of Wales' early photoshoots reveals that she wore Elizabeth Arden's pencil in 'Blue kohl 636', which she teamed with a co-ordinating mascara from the same brand.
But as the years went by, Diana began to embrace a more natural, neutral look - which her makeup artist Mary Greenwell has since revealed was all down to her.
WATCH: Princess Diana's boldest beauty looks
Speaking to Yahoo!, Mary said: "I think beiges and browns are just so much prettier. Simple as that."
She added of Diana's more classic look: "She was someone who was in the public eye presenting herself all the time to the public. It isn't particularly appropriate to go on changing your look every five seconds."
Wearing electric blue in 1988
Mary did reveal that Diana still loved to play with makeup, however. "She loved makeup and loved experimenting. It wasn't to the point of going from green eyeshadow to blue eyeshadow, but just experimenting with ways to bring her eyes out more. It was just much more about really getting her to look absolutely beautiful all the time."
Pictured in 1995 wearing a more classic liner look
The iconic royal may have moved towards neutrals in her later career, but series four of The Crown has certainly brought her signature blue eyeliner back to the public's attention - so much so that sales of the bold product have shot up, according to beauty retailer Escentual.com.
We've rounded up some of our favourites below...
Elizabeth Arden High Drama Eyeliner in Midnight Dream, £14.75. Escentual
Make like Diana and opt for a creamy Elizabeth Arden pencil! Draw along the lashline and then smudge at the root for a lived-in look.
Marc Jacobs ultra-skinny gel crayon in Code Blue, £19, Net-a-Porter
The ultimate electric blue, this highly pigmented crayon glides on super smoothly - you can be really precise with it, too.
Super colour eyeliner, £6.99, Kiko
Fancy a flick? This liquid liner is ultra-pigmented.
YSL mascara in Extreme Blue, £21, Look Fantastic
Go for the full Diana by adding lashings of blue mascara - YSL's offering is the perfect electric shade.
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