While he saw colours in dreams as repetitions of colours seen and remembered from the day before, he also showed that symbolic colours in dreams were superego manifestations. For example, a young boy dreamt of the holy grail and in this dream a crimson light streamed from it and seared his eyes. The searing of his eyes, according to Freud, was a castrating punishment for viewing the primal scene, as well as indulging in passive masochistic surrender.
Jung, on the other hand, considered that the psychological symbol was an attempt to
elucidate by analogy what was as yet unknown and still in process of formation. In other words, the symbol was both charged with psychic meaning and in the process of developing and moving towards solving a dilemma. In Jung's great works, the Psychology of Alchemy and the Mysterium Coniunctionis, he describes the developmental process in alchemical terms passing from the Blackening or Melanosis to the Whitening or Leucosis and from the Xanthosis or Yellowing to the Iosis, the Reddening.