Iris
Ἶρις
The messenger who crosses between sky and earth on a bridge of rainbow.
If Hermes is messenger of the gods, Iris is above all the messenger of Hera.
The whole idea of this goddess is that the rainbow is a road linking heaven and earth.
The iris of the eye, the iris flower, and the word iridescent — light shimmering in rainbow colors — all come from her name.
SourcesHesiod, Theogony