"Father, why do old people have grey hair?"
"Son, it has to do with death. We know people go grey when they are approaching death. The first person to approach death and go grey was Orlanth. His brother had understood the power of death, and Orlanth wne to borrow it from him. As he approached, he became fearful. You know how the color drains from your face when you are afraid? Well, everything then was more than it is now. And death was so fearsome that the color drained not just from Orlanth's face, but from his hair, too. That is why people go greay as they get older. You should also know that this tells you something about Yelm's people. Their hair starts off with nearly no color in it. They are fearful from birth."