Abstract: The semantic expansion and syntactic features of the color word "black/white" in Fortress Besieged are analyzed based on the words (groups) or phrases formed by the basic color word "black/white" in Fortress Besieged and the theoretical framework of implicit metonymy and cognitive grammar. Metaphor, metonymy and implicit metonymy are the three universal cognitive mechanisms behind the semantic expansion of the color word "black/white" to form many different meanings. The semantic highlighting and scanning patterns in cognitive grammar theory provide the rationale for the different syntactic functions of color words "black/white".