Nutri Color Filters Toning filters are for preserving an already dyed shade, not changing your hair color, for example from blonde 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 shade? The first number in the TONING FILTER shades stands for the darkness mode. Tex 931, is on a base of extra light blonde (9), and contains the shades gold (3) and ash (1). Use: Distribute in shampooed and towel-dried hair. Leave on for 3 minutes to refresh the hair shade.