Use the Material Parameters rollout to set the color of hair. These parameters apply to buffer-rendered hair generated by Hair And Fur. In the case of geometry-rendered hair, the hair coloring is derived from the growth object. In the case of hair rendered by “mr prim”, all parameters apply except Self Shadow and Geom. Shadow. With instanced hair, Hair And Fur uses the material from the instanced object
Additionally, you can apply a map to any value by clicking the blank button to the right of the parameter. Values in the map act as multipliers to the base value.