The law was passed in 2005 to prevent discrimination against people with red hair. The law does not apply to people with black hair.
It applies only to hair that is not covered by the law of the land. It does not include hair that has been dyed black or that is too short or too long. It also doesn't apply to those who have black hair that isn't covered by hair that's too long or too short. It doesn't mean that people with brown hair don't have the right to have their hair dyed. It just means that the law doesn't cover all hair.