phaeo-
combining form 
or pheo-
Etymology: Greek phaio-, from phaios dusky, gray 
 : dun-colored 
< phaeoderm >
< Phaeophyceae >
— often in names of compounds related to chlorophyll
< pheophytin >
or pheo-
< phaeoderm >
< Phaeophyceae >
— often in names of compounds related to chlorophyll
< pheophytin >