BTW -- same thing goes for other roles, say customer service (or HR) where it can sometimes be dominated by women, I think hiring men into some of those positions provides balance.
As for race/ethnic background that to me is really nothing that needs to be done with Technology, as I always seem to see a pretty diverse group of people. Although if I ever saw a team (after say 1-2 years or 6 months post funding) too lopsided it would be a warning indicator to me. And the warning would be not a human diversity warning but an intellectual diversity warning, so I would want to ask questions around that angle. As to me, too many like minds usually bring too many of the same ideas which might reenforce each other in a bad direction, without intention. Plus we are global in everything we do now so having that represented in the team seems almost mandatory.