Hair color!?

Okay, so I'm am absolutely hair bi polar. I am a natural blonde with 'gunmetal blue' eyes (they're usually more gray than blue). I have gone brunette before and I loved how it made my eyes stand out. But I'm very bubbly, so I feel like blonde fits my personality better. My question is..how do you judge hair color? What do you think is more attractive? Blonde hair/blue eyes? Or brown hair/blue eyes? What do you think MEN find more attractive?