To "tussle" your hair is to playfully mess up one's hair.
Can be either dependent upon usage. She had brown hair. He had a few grey hairs.
you should be more specific but im pretty sure your thinking of Just the Way You Are - Bruno Mars
blond hair
Neither well sometimes it can be human HAIRRR!
Neither, but if you need or want one than the hair booster is better, and healthier.