This is Iris. She is a messanger of the gods and the goddess of rainbow. She is also know as the goddess of sea and sky and is represented as supplying the clouds with the water needed to flood the world, consistent with her identification with the rainbow.
There are 8 steps to drawing an ancient goddess and 7 of them happen before you actually start to draw. :) If you want to know what they are, you know where to go.
Linking to the Artists in Blogland as well.