In Kabbalistic thought this represents a symbolic vision of alchemic powers in visual nature. Within Jacob’s dream the «ladder» symbolized a «rainbow,» or a prismatic staircase, extending between heaven and earth; furthermore, the red and blue were the original colors–with the first characterizing the «spirit,» and the second representing «matter»–and from them comes orange, yellow (through a mixture of the light of the sun), green and violet.
The sun is thought to be the alchemic gold while the moon is the alchemic silver. These two are the rulers of the world, astrologically perceived, from which all things are made. A.G.H.