When you call something dusty, it's either literally covered in dust or so old and unoriginal that it might as well be. You can use a feather duster to clean off dusty surfaces, but if something is a dusty color, that just means it's got a grayish tint to it, like dusty pink or dusty blue. If places, roads, or other things outside are dusty, they are covered with tiny bits of earth or sand, usually because it has not rained for a long time.

Understanding the Context

They started strolling down the dusty road in the moonlight.