Unconventional hair colour is all the rage

Pastel pink hair and unicorn highlights used to be the go-to styles for those born in the early 1990s. But recently the trend has transcended all ages groups. From actress Dame Helen Mirren to lapsed pop star Danni Minogue, the over 40s are becoming increasingly more receptive to beauty's boldest hair trend.

"More and more women are asking for vibrant and colourful shades when they come to the salon," says L'Oreal Professionnel colour ambassador Jack Howard.

''Today it's much easier to incorporate pastel tones through the lengths of the hair, and going semipermanent is a low-commitment option that appeals to all ages - not just millennials."

Local Carlton Hair stylist Kim Hickman agrees, suggesting that social media could be a catalyst for the trend as women have become accustomed to seeing change and variation in the beauty industry.

''Clients of all ages are more daring with their make-up and wardrobe choices, meaning that they don't have to play it safe when choosing a new hair colour," she mentioned at a winter hair trend presentation at Carlton Hair Hyde Park last week.

Over 2.8million users have posted with the hashtag #pinkhair; more than 1million have used #mermaidhair and #greenhair; and there are already over 227,000 posts for #colorfulhair on Instagram alone.

Now the full colour spectrum is being celebrated, rather than the traditional blonde, brunette and red hues, whether you want super-bright highlights or soft, muted pastel tones.

Colour is no longer permanent, lasting anywhere between four to 12 washes, depending on the brightness of the shade you opt for, making colourful shades like pink and coral commitment-free.

You can be blonde at the beginning of the week and pink at the end, says Hickman.

A collection of home dyes consisting of playful colours from Davines allows stylists to colour your hair intensely in the salon and give you a tub for upkeep or colour changes at home.

The latest advancements in product also mean that colouring causes less damage to hair.

Celebrity hairstylist David Gillson adds: ''The new hair colour treatments leave the decisions up to the client - you could have bright pink hair for a weekend, for Africa Burn for instance, and go back to your blonde law-office bob on a Monday," he says.

While the idea is that anyone of any age can sport rainbow-coloured hair, there are a few key rules worth playing by.

Pastel hues work best on pre-lightened or naturally light- blonde hair.

"The blonder you are the better pastelised colours will show up and last longer ," says Hickman.

''Subtle flashes of colour work best on brunettes."

Coloured hair pieces for peekaboo are a good idea as well.

The other advantage of a consultation is that hair colour works best when the correct shade has been positioned to frame and compliment the skin. This is something that can only be created by a professional. - Andrea Nagel and The Daily Telegraph

• Contact David Gillson and Kim Hickman at Carlton Hair, Hyde Park

• This article was originally published in The Times.