Can't Texture Hair

Hello All!
So the two level 3D demo, I have been making (with collaborators) of my game concept, is finally near completion. For some reason, though, Unity won’t let me drag a material onto one item in the game, which happens to be one of the character’s hair. What could be the problem?

If drag and drop does not work, select the hair object and look at the “Skinned Mesh Render” or “Mesh Renderer” Component. There you can find a small drop down called Materials.
That is a list of all the material currently assigned to the Rendeler.
You can select the small circle on the right side to select what new material you would like the have instand of the current one.