People can’t get enough of the Instagram root right now.

The hair trend, that is. (Get your mind out of the gutter!)

London-based celebrity hairdresser and stylist Jason Hogan told Glamour it was the “hottest look” for the upcoming season.

Also referred to as “root shadow” it’s about growing out your hair colour and letting your natural roots show without rushing to the salon for a touch up.

"This is a technique we use quite a lot... it was a big nineties colour story however in the 90s the shadow was much more contrasting and had a grunge feel due to hair being worn flatter and with a more matte finish," explains Elizabeth Shedwick our Head of Technical Varder at TONI&GUY Australia.

Think Drew Barrymore, Courtney Love or Angeline Jolie in her blonde and erm, slightly off the rails, days.

However there's an important update to the version we're seeing at the moment on A-listers like Margot Robbie and Jennifer Lawrence.

"Hollywood’s revival of the insta root is a lot more polished and used as a way to make the regrowth bottle blondes must suffer a little more expensive looking and more achievable for those not blessed with a scandi-esque natural base shade," Shedwick says.

If you're after it for yourself, ask your hairdresser for "root shadow".

"The technique would be done by foiling/balayaging as usual and then applying a root stretch the same colour as your natural hair to stretch down the hair," explains Tarryn Cherniayeff, Founder and Director of boutique hair salon, Mob Hair in Bondi.

"Instead of blending down as I would usually for a seamless root to end blend, I would stop about an inch from the root almost creating a regrowth."

Even better, it's a hair trend that works for anyone.

"It allows people who wouldn’t necessarily be able to go as blonde (due to a shocking regrowth) the option of having a much lighter style, without it looking awful within a week or two," Shedwick says.

"It also works for people with a lot of volume as the depth in the root will make it appear flatter giving the hair a more contemporary/editorial feel, whereas blonde straight from the roots gives height and volume."

While it's popular with blondes, she says it can work for any colours that are lighter or brighter than your own natural base shade.

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"On a brighter base, for example a brighter copper the roots could be made more subdued and slightly cooler to blend better with a client’s own natural base shade."

To have it purposefully put in would still require a regular eight week appointment routine, but if you're looking for an excuse to skip our root touch up, you now have a name - and Hollywood's seal of approval - up your sleeve.

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