The grey hair in the story could represent the years of life, the experiences, the trials and tribulations that a character has gone through. Meanwhile, the black beard could be a mark of his individuality. It could be that in the story's context, having a black beard while having grey hair makes the character stand out. It could be a sign of his non - conforming nature or his unique genetic makeup that is part of the plot. For instance, it could be that others in the story with grey hair don't have black beards, and this makes him different and special in some way, which drives the story forward.
I'm not sure which specific 'grey hair and black beard story' you are referring to. There could be many stories with such elements. It could be a story about an old man with grey hair but a still - black beard, perhaps a story of wisdom and experience related to his appearance.
The Neverending Story is a well - known fantasy film with a specific set of actors from its time of production. Jack Black is a great actor in his own right, but he was not involved in this classic movie. If you were thinking of someone who looks or acts like Jack Black, it still wasn't him in this movie. This movie has a distinct cast that helps create its unique atmosphere and story.