Not sure if they still sell the product, but you can also use a 'toner' on your hair. It is a rinse out product so needs to be repeated constantly but it's cheap stuff. It's not a colorant, per se, just adds a bit of 'dimension' as it were. I used to use it all the time but stopped it as well as any coloring once the grey was significant enough for none of the colorings to matter (to me).