Here I spoke about how a problem had caused Nick’s hair to look blue. I was using some transparency effects on the hair to let it fade away like real hair. (I was following the hair tutorial in “Introducing Character Animation with Blender”) However, I am using ray tracing for transparency to have good looking transparency in glass and other things. So I also have to use it for the characters.
I almost suddenly realized what the problem probably was! I remembered that I had to turn on “Ray Transp” in the Mirror Transparency Tab for materials.
Now to just fix the hair so that it looks a bit more realistic.