We're still thinking about this prim all-white look Kate Middleton sported over 10 years ago

Kate Middleton is a true vision in this all-white ensemble that she wore at Derby Day in 2011, marking one of her only all-white outfits since her wedding dress.

There are a few unspoken fashion rules that we've noticed over the years Kate Middleton follows - for one, she rarely ever wears the color orange. Well, except for that one time she wore a peachy-orange peacoat in a rare display, or that time she sported a truly glorious orange beaded bag with a wooden handle. We digress. 

Another fashion standard Kate typically seems to stick to is not wearing ensembles of all white - but we recently found a picture of the Princess from over a decade ago of her wearing an all-white ensemble that still holds up as a truly incredible sartorial display.

While attending the Derby Day at the Investec Derby Festival in 2011, Kate sported a beautiful all-white dress that featured a billowing, flowy hem on the bottom. On top of her white dress, she paired a matching clean white tweed coat, creating a fresh look for a day of horse race observing.

To accessorize this all-white ensemble, she chose a pair of nude pump heels (a wardrobe staple she still uses frequently, even over a decade later), as well as a small nude clutch bag and a pair of dangling yellow gem earrings. She also wore her hair slicked back into a bun - a hairstyle that is still incredibly trendy today.

For makeup, the Princess went with a soft glam look so as to not distract from the freshness of the rest of her outfit. 

On the rare occasion that Kate does wear an all-white ensemble, she clearly looks amazing - just as she did when she wore this Princess Diana inspired white power suit a year ago, which she paired with a (get this) orange blouse. Yes, the Princess paired her two least-worn colors together to form a totally chic spring outfit. 

How to get Princess Kate's all-white Derby look

The formula for this outfit is simple - white dress, white jacket, nude shoes - and you're good to go.

Rise to the Occasion White Midi Wrap Dress, £53 ($69) | Lulu's

A flattering wrap silhouette starts at a surplice bodice, framed by fluttering short sleeves, then carries into a sweeping midi skirt - pair it with a white jacket for the ultimate Kate Middleton vibes. 

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Odette sweater lady jacket in cotton-blend bouclé, £138 ($178) | J. Crew

Somewhere between a jacket and a cardigan, this easy layer is perfect for days that feel somewhere between seasons.

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