Image copyright Eileen Carey

A Silicon Valley CEO reveals her secret to getting ahead in business - dyeing her blonde hair brown, and ditching her heels and contact lenses.

Eileen Carey is a successful CEO, in her early 30s, with glasses and brown hair.

But she didn't always look the way she does now.

"The first time I dyed my hair was actually due to advice I was given by a woman in venture capital," she says.

Carey was told that the investors she was pitching to would feel more comfortable dealing with a brunette, rather than a blonde woman.

"I was told for this raise [of funds], that it would be to my benefit to dye my hair brown because there was a stronger pattern recognition of brunette women CEOs," she explains.

Pattern recognition is a theory which suggests people look for familiar experiences - or people - which in turn can make them feel more comfortable with the perceived risks they are taking.

When she had blonde hair, Eileen says she was likened to Elizabeth Holmes, whose company Theranos has been through a lot of controversy.

"Being a brunette helps me to look a bit older and I needed that, I felt, in order to be taken seriously," Carey says.

Image copyright Eileen Carey Image caption Eileen Carey used to have blonde hair and wear contact lenses

In interviewing candidates for roles at her startup, Glassbreakers, which provides companies with software aimed at attracting and empowering a diverse workforce, she's encountered other blonde women who have also dyed their hair brown.

"We discussed that there's the fetishisation of blondes," says Carey.

"People are more likely to hit on me in a bar if I'm blonde. There's just that issue in general.

"For me to be successful in this [tech industry] space, I'd like to draw as little attention as possible, especially in any sort of sexual way."

It's not just hair colour either. Carey has swapped her contact lenses for glasses and says she wears loose-fitting "androgynous" clothes to work.

She says, in a male-dominated working environment, her old look made it more likely she would be flirted with.

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"I want to be seen as a business leader and not as a sexual object. Those lines are still crossed very often in this space," she explains.

Even so, Carey admits that sexual harassment against women in work or other public spaces is all too common.

"There's a problem in our industry, period, around sexual harassment," she explains.

At a recent party for software company executives, cocktails were served by paid female models, who were "dressed like fairies".

Being one of the few female CEOs in the room, Carey says she was in the minority when it came to seeing the situation as inappropriate and unprofessional.

Image copyright Lauren Hepler Image caption Glassbreakers provides companies with software aimed at empowering a diverse workforce

She says her mother, Eileen Sr, has been a massive influence on the way she approaches masculinity and femininity, and gender issues in general.

Both Carey's mother and her aunt were feminists back in the 1980s.

"My mom has short hair, never wears makeup, does not wear high heels, never wears dresses. That's who she has always been," Carey says.

In the past Carey had her hair blow-dried professionally, her nails manicured.

Now she declares herself "very much my mother's daughter, where I don't like wearing makeup, and I don't like wearing heels. I just like being comfortable at work."

Image copyright Eileen Carey Image caption Eileen with natural blonde hair

Carey doesn't feel the same pressure to be feminine as women who were brought up in more traditional cultures or households. "I was very fortunate that I didn't have those gender stereotypes placed on me at a very young age."

With news stories about sexism and gender in the tech industry - from Uber to Google - dominating the headlines, Carey says employees must remember they have a choice about where they work.

Find out more

According to a 2016 survey of Silicon Valley, 60% of women working in tech experience unwanted sexual advances

Sexual harassment accounted for nearly 30% of the 91,503 cases of workplace discrimination complaints filed that year

But there may be many more cases - a 2013 poll suggested 75% of those who experienced sexual harassment at work did not report the incident

Trying to change a culture alone from within a company can be difficult she says, and can lead to employees feeling very wounded - leading potentially to "a million papercuts, the micro-aggressions, the little things".

If you want to try and change a company, then "Be the change you want to see in the world, which may mean sacrificing your personal life for a discrimination lawsuit. That's unfortunately how you have to change businesses."

Otherwise, she says: "Go where you are going to be successful."

Companies that aren't inclusive, that don't make spaces for women in leadership, that make it difficult for women to be retained, are not going to win in the long term, she explains.

"Look at the numbers. Look at the leadership. Talk to women who work there. If that doesn't seem like a place that you can reach your highest potential, don't work there."