No it was not a wig.  This was a girl who floated occaisionally to the fringe of my group of friends when I was in Jr. College.  Her hair was naturally that darkish dishwater blonde, but every few weeks she used a temporary dye to dye it bright pink.  The color sort of floated on the top of her hair, so you could still guess at its natural color.  Her hair was usually unbound when I saw her.  Can you imagine?