Facebook CEO Mark Zuckerberg spoke about his grey shirts, which are known to be his fashion staple. However, his explanation about why he commonly appears in public in a grey shirt may sound offensive to feminists.

"I'm in this really lucky position where I get to wake up every day and help serve more than a billion people. And I'd feel I'm not doing my job if I spent any of my energy on things that are silly or frivolous about my life," Zuckerberg explained.

The 30-year-old billionaire seemed to imply that caring about appearance or clothing undermines the ability to work, and the way he described dressing professionally as "silly or frivolous" may be interpreted as a statement against Yahoo! CEO Marissa Mayer, according to New York Magazine.