Nutri Color Filters Toning filters are for preserving an already dyed shade, not changing your hair color, for example from blond to dark hair. Nutri Color Filters are a direct pigment, which means that they are fully developed pigments, which are deposited on the outside of the hair shaft. It is not a permanent color or tint. The durability of Nutri Color Filters depends on the porosity of the hair, how often you wash your hair and what you wash it with. How do I choose the right toning? The first number in the TONING FILTER shades stands for the darkness mode. Tex 642, is on a base of dark blonde (6), and contains the shades copper (4) and iridescent/violet (2). Use: Distribute in shampooed and towel-dried hair. Leave on for 3 minutes to refresh the hair shade.