Who was the goddess of the rainbow?

Iris is recognized as the goddess of the rainbow in Greek mythology. She serves as a messenger for the gods and is often depicted as a beautiful figure with wings, using the rainbow as her means of travel between the worlds of mortals and gods. Iris represents not only the physical phenomenon of the rainbow but also conveys messages, connecting the divine with humanity.

Athena, on the other hand, is primarily known as the goddess of wisdom, warfare, and crafts, holding roles that extend far beyond the symbolism of a rainbow. Hera is the queen of the gods and associated with marriage and family, while Eos is the goddess of the dawn. Each of these figures plays significant roles in Greek mythology, but none are directly linked with the rainbow in the way Iris is. Thus, the connection of Iris to the rainbow makes her the correct choice.