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.
Highlights give the hairstyles small coloured strands, and depending on the colour you can use them to give depth to the texture with darker colours, or go the opposite way and have fun with pastel colours.
Gray and white colours makes the hair go salt & pepper allowing you to can make your sims’ age progression more natural. For example, you can first use gray highlights on your sim hair, and later, use gray colour as base with the previous colour highlights.
More info and examples here