Description
With The Chromatic Collection: Extras you can mix many colours for your sims hair, making their hair look unique. The extras consist on 4 different set of textures that you can combine in CAS and two extra styles per hair.
With ombré you can add a coloured gradient to the hairstyles, like making a brunette feel that it has been touched by the sun with some gold tones, or go wild and pick any of the pastel/vibrant colours of the collection.
More info and examples here