Why brunettes have more fun (especially on pay day)

And it's not only in their chosen careers that brunettes will be more successful - they are also luckier in love too. 

Almost half (44 per cent) of those with dyed or natural brown hair said the shade gave them the greatest success with the opposite sex - a 10 per cent better hit rate than blondes.

Brunettes like Catherine Zeta-Jones, left, and Eva Longoria, right, will earn more and have more luck in love than blondes, a study shows

And 20 per cent of brunettes boasted five relationships or more in the past, while only 13 per cent of blondes shared the same amount.

Camila Lobo-Guerrero, of hair colour specialists Schwarzkopf & Henkel, who commissioned the report, said: "It's always assumed blondes have more fun, therefore had more success in their love lives and careers too.

"Our research shows that blondes still do have more fun but aren't taken as seriously as women with darker hair - both at work and play.

Blonde Ambition: Pamela Anderson, left, and Paris Hilton, right, have more fun, says the study, though whether they earn less than brunettes is open to debate

"Brunettes are climbing the career ladder quicker as well as having better luck in love which may explain why stars like Catherine Zeta-Jones, Kelly Brook, Kate Beckinsale and Eva Longoria-Parker are so successful.

"Hair colour can not only change your appearance but also change your mindset and people's perception of you too."  The Schwarzkopf & Henkel study also showed just how much hair dyeing can influence a woman's outlook on life.

One in seven females admitted that changing their natural hair colour made them feel sexier - with those born with dark hair feeling the most desirable after altering their look.

Plus a further 20 per cent of women said that dyeing their locks made them feel happier and more confident with their appearance.

But when it came to the main reason women coloured their hair, 40 per cent said they simply hated the natural tone of their tresses.

Almost half of women even went as far as saying they couldn't ever imagine not having dyed hair.

With the average women first dyeing their hair at 20, it's unsurprising that 15 per cent of hair-dyeing fans said they couldn't actually remember what the true hair colour looked like.

Women love changing the shade of their locks so much, the average hair-dye fan will try out four different shades during their life.

Red is the tone most women test out first but the colour they stick to the least - lasting two years in a woman's hair colour life-cycle.

Black shades fair a little better at three years and women will sport brown tints for four years.

But despite better earning and love-life potential, it is fun women obviously hanker for as the average woman who fakes it will colour their locks blonde for the longest time, lasting six years.