Final answer:
A color-blind boy's parents and grandparents all have normal vision. The genotypes can be represented as: Boy (XcY), Mother (XCXc), Father (XCY), Grandmother (XCXc), and Grandfather (XCY).
Step-by-step explanation:
A color-blind boy's parents and grandparents all have normal vision, which means that the color-blindness trait is recessive in this family. Color blindness is an X-linked recessive trait, meaning it is carried on the X chromosome. Since the boy's parents and grandparents have normal vision, they must have one normal allele and one recessive allele for color blindness. Therefore, the genotypes of the family members can be represented as:
Boy (color-blind): XcY
Mother (carrier): XCXc
Father (normal vision): XCY
Grandmother (carrier): XCXc
Grandfather (normal vision): XCY