I have the solution! (I think)
There's an old character I use from time to time called "Granny Gumms" I actually just learned the secret of how her hair was made from the woman that built her a few days ago - find long fun fur that is grey/black - that is grey at the top and black near the "roots", brush it back and add a mixture of white glue and water. When it dries it will look great.
Check out
this photo and if it's sort of the look you are going for maybe I can provide more detailed information.