IRIS ~ THE GREEK GODDESS OF THE RAINBOW

In Greek Religion, Iris ( Ίρις) is the Goddess of the rainbow and Messenger of the Gods. She is often described as the handmaiden and personal Messenger of Hera. Her father is Thaumas ( the Wondrous ) a marine God, and her mother is Electra ( Amber ), a cloud Nymph. She is therefore closely connected to the sea and the skies. For the Greeks, a nation with strong ties to the sea, the rainbow's arc indicated that the Goddess provided the clouds with water from the sea-and the rainbow was often seen as a manifestation of the Goddess Herself. 

Iris is depicted in ancient Greek art as a beautiful young woman with golden wings, a herald's rod (kerykeion), and sometimes a water-pitcher (oinochoe) in Ηer hand. She is usually standing beside Zeus or Hera, sometimes serving nectar from her jug.During the Titanomachy, Iris was the messenger of the Olympian Gods, while Her twin sister Arke betrayed the Olympians and became the messenger of the Titans. Iris also mentioned as a wife of Zephyros, the God of the West wind, although she is referred to as a maiden in some sources. Iris links the Gods to humanity,by delivering their messages. She travels with the speed of wind from one end of the world to the other, and into the depths of the sea and the Underworld.Iris is frequently mentioned in the Iliad.

According to the "Homeric Hymn to Apollo", when Leto was in labor, before giving birth to Apollo and his twin sister Artemis, all the Goddesses were present, apart from two;  Hera and Ilithyia, the Goddess of childbirth. On the 9th day of her labor, Leto told Iris to bribe Ilithyia and ask for her help, and keep it a secret from Hera. 

According to Apollonius Rhodius, Iris intervened when the Argonauts Zetes and Calais, chased the Harpies to the Strophades ("Islands of Turning"). The brothers had driven off the monsters ,which were torturing Phineus. Iris asked the Argonauts to spare the lives of the Harpies, and promised that they would keep away from Phineus.

As a Goddess, Iris is also associated with communication, messages,  and new endeavors.In some texts, She is described as wearing a coat of many colors. With this coat she actually creates the rainbows she rides to get from place to place. Her wings are said to emit so much light, that can light up the darkest of places. 

Though Iris is principally associated with communication and messages, she also helps the fulfillment of humans' prayers, either by fulfilling them Herself or by bringing them to the attention of the other Gods and Goddesses.

There are no known temples or sanctuaries to Iris; and while She is frequently depicted on vases and in bas-reliefs, no statues of Hers have been found until now. 

Ancient sources tell us that Iris was worshiped on the Sacred Island of Delos- the devotees offered Her cakes made of wheat,honey and dried figs. This is the only evidence known about her cult, which seems to have been minor.

EDITED FROM: Wikipedia