Further, 25% of hair dye users plump for a non-natural shade, and a temporary hair colour boom saw sales rocket 48% between 2016-17.
When it comes to preferred hair colour for dyes, blonde is out in front.
Last year 42% of Brits who coloured their hair* transformed their tresses blonde - with a bold 18% opting for the platinum look.
Meanwhile, just over a third (36%) of hair dye users plumped for brown locks, 17% chose an auburn/red mane and just under one in ten (8%) went black.
The research was carried out by Lightspeed among 2,000 internet users aged 16+ in January 2018, and Mintel's Hair Colourants UK 2017 report is available here.
Alex Fisher, Senior Beauty Analyst at Mintel, said: “As the majority of Brits have naturally darker hair, lightening their locks blonde is the nation’s most obvious hair colour solution.
“A blonde base also gives more radiance to non-natural shades, so those hoping to make the most of temporary bright or pastel colours are likely to go blonde first.
“Although natural colourant shades like brown and blonde are still the most popular, increasingly more casual attitudes in the workplace mean there is less need to shy away from non-natural shades.”
Non-natural colours, and natural brown
Highlighting a interest in trendy shades, according to Mintel an adventurous 25% of users ventured for non-natural choices such as pastels and bright colours, mimicking the hugely popular unicorn trend.
And while Brits of a certain age battle with their greys, one in twenty (5%) hair dye users opted for the grey/white look.
But while blonde is the nation’s preferred hair dye of choice, Brits are most likely to have natural brown barnets.
Almost half (48%) of Brits are natural brunettes, around three in ten (29%) are natural blondes and 8% have natural black strands.