Take the peroxide plunge and have a blonde moment like Kim and Lily

05/03/2015 File photo of Kim Kardashian arrives at Lanvin's ready-to-wear Fall-Winter 2015/2016 fashion collection, part of the Paris Fashion Week. See PA Feature BEAUTY Going Blonde. Picture credit should read: AP/Jacques Brinon/PA Photos. WARNING: This picture must only be used to accompany PA Feature BEAUTY Going Blonde. UK REGIONAL PAPERS AND MAGAZINES, PLEASE REMOVE FROM ALL COMPUTERS AND ARCHIVES BY 24/04/2015.
05/03/2015 File photo of Kim Kardashian arrives at Lanvin's ready-to-wear Fall-Winter 2015/2016 fashion collection, part of the Paris Fashion Week. See PA Feature BEAUTY Going Blonde. Picture credit should read: AP/Jacques Brinon/PA Photos. WARNING: This picture must only be used to accompany PA Feature BEAUTY Going Blonde. UK REGIONAL PAPERS AND MAGAZINES, PLEASE REMOVE FROM ALL COMPUTERS AND ARCHIVES BY 24/04/2015.

When Kim Kardashian West unveiled her dramatic new do at Paris Fashion Week in March, brunettes the world over wondered: just how did she get her dark locks so light?And with Lily Allen and Carol Vorderman recently taking the peroxide plunge too, salons have seen a spike in calls from would-be blondes.

“We’ve already had so many calls from people who are desperate to copy Kim’s look, particularly darker brunettes who are looking for a complete colour overhaul, rather than blondes who just want to go a few shades lighter,” says Marc Trinder, art team director at Charles Worthington Salons.

But despite regular root touch-ups (all captured on Instagram, of course), Kim reverted back to her usual ebony shade in three weeks.

Does that mean such high-maintenance hair is unsustainable, even for a millionaire who has her own ‘glam squad’ on hand?

“The lightening process from very dark to very light blonde is heavy and strenuous on the hair,” warns Claire Bonney, senior technician at Radio Hair Salon. “It involves bleaching the hair, pushing it as light as it will go, possibly a double application, and of course, a much-needed toner to knock out any brassy tones.”

DON’T DYE THIS AT HOME?

So is Kim’s black-to-blonde bleach job achievable with an off-the-shelf dye?

“I would not recommend this as DIY, I have seen too many disasters,” says Tracy Hayes, global head of technical training for Fudge Professional. “Always have this process done professionally, to keep your hair in the best possible shape.”

If you have warm brown or ginger hair, you should avoid the peroxide too - unless you want to end up with orange locks.

“The red pigment is really hard to lift,” says Nice’n Easy UK colour advisor Jonathan Long, but medium to dark brown hair can be lightened: “I would always recommend shifting a shade within one to three shades of your current hair colour.”

If you are tempted by the DIY route, then the greasier your hair is, the better, as the oils will help protect your scalp.Follow with a toner to avoid a brassy finish: “Lightened hair tends to pick up pollutants that can make the hair appear yellow in colour. In order to neutralise these tones, I would recommend using LIVE Toner Mousse Icy Platinum M01,” advises Sian Hickson, Schwarzkopf Brand Manager.

Aftercare is crucial too.

“Use shampoos and conditioners specifically for either colour-treated hair or dry and damaged hair, and use a treatment once or twice a week,” says Hickson. “Towel dry the hair before applying conditioner, as this will ensure that the conditioner penetrates further into the hair, and avoid using excessive heat on the hair, be it straighteners, wands or tongs.”

TIME TO GO PRO?

So your natural hair hue is too dark for at-home application, but what next? There’s still a lot to consider before you book in for your big blonde makeover.

“This is a huge job and will need the eye and attention of a colour specialist. Getting an even result on previously coloured hair can be difficult, depending on the history of the hair,” says Claire Bonney.

It’s not cheap, either.

“I would say between £200 and £300 for the initial application, and £120 and £170 for the root application, depending on the salon - some high-end salons will be more expensive than this,” Tracy Hayes estimates, and you’re looking at touch-ups every six to eight weeks.

Looking after your locks post-peroxide is even more important when it’s a pro job.

“The process is chemically drying on the hair, so using professional products at home is imperative, as you must feed the hair the protein and moisture it needs. Regular haircuts are important too,” Bonney advises.

With that level of upkeep, no wonder Kim didn’t keep her new colour for long.

But that’s not to say you can’t realise your own blonde ambition, Hayes says, “as long as you are prepared to spend the time and money to keep it looking good.”