Hair and skin tone is not used in recognition. The points to build the model are taken from eyebrows, eyes, nose and mouth. So as long as you don't have hair covering your eyes it won't affect anything.

Also, face recognition technologies are better than described in the comments; you can take a photo of a random person from the street and successfully find their social network account with publicly available sites. Compared to this, recognising just several hundred faces looks like an easy task.