Thank God this one is over, it's been running for bloody months. I'll admit, this is one of those cases that strays very close to the line of what is acceptable and unacceptable in hiring your staff.
The bottom line is that you're going to really struggle to justify in most professions that you need a certain 'look'. There are times when you could specify a level of attractiveness, or a certain ethnicity, but hairdressing is not one of those in my opinion.
The debate over acting has reared it's head. There are parts that require a certain ethnicity. You can't have a black Winston Churchill, and you can't have a white Martin Luther King. But unless based on real people, most parts don't have to be racially specific. I see no reason why you can't have a black Joseph, or Nancy etc. Look at the Shawshank Redemption - Morgan Freeman is playing the part of Red, written as a white Irishman. And a fine piece of casting it is too.