The Zohar has much to say about dreams and how and who interprets them. When Pharaoh learned that there was a reliable interpreter, he had Joseph quickly released from jail to hear his understanding. Joseph (whose Sephirot color is purple associated with Yesod, connections) here explains to Pharaoh that he is not the source of interpretation but that he is channeling what Hashem shares. And in Zohar the seven fat cows that predicted seven years of abundance were also representing the seven lower Sephirot (aspects of Hashem that create our world, each with a color associated with it) that were flowing from the Holy One for the health of the land. Pharoah couldn’t see this, but Joseph did, and the cows coming from the water the Zohar relates to Joseph who is associated with the rivers and the flow of Hashem’s gift of water to all of us from the sky, here in the image flowing into the river.