Final answer:
Eosin primarily stains the cytoplasmic features of cells, giving them a distinct red to orange color.
Step-by-step explanation:
The eosin stain primarily stains the cytoplasmic features of cells. When stained properly, the granules of eosinophils, a type of white blood cell, will have a distinct red to orange color. The nucleus of the eosinophil will typically have two to three lobes.