As I assume you're taking about head hair it would be
Mes cheveux sont... (beware, it's plural in french)
His hair is "ses cheveux" (masc.) in French.
a hair bun is 'un chignon' in French.
Long hair is "les cheveux longs" in French.
ginger hair is 'les cheveux roux' in French.
'messy hair' in french is 'cheveux en désordre'
You can say "Il a des cheveux gris" in French to mean "He has gray hair."
les cheveux
Coiffeur
les cheveux
mes cheveux
An hair tie is "un élastique à cheveux" in French.
You would say "cheveux lisses" in French.