* Salt and pepper: This is the most common and widely understood term. It implies a mix of gray (salt) and the original hair color (pepper).
* Grizzled: This suggests more gray than original color and can imply a rugged or distinguished look.
* Graying: This is a general term that simply means the beard is turning gray.
* Silver streaks: This is more specific if the gray is a bright, shiny silver color.
The best term to use depends on the context and the specific look you want to describe. "Salt and pepper" is generally a safe and well-understood option.