There is controversy in the literature as to whether dreams are essentially black-and-white phenomena to which color elements are sometimes added or are originally completely colored perceptions whose memory traces are subsequently "bleached" to varying degrees by repression and other mechanisms. The evidence in either direction is inconclusive and the issue should be considered to be a moot one.

A completely colored dream is one variety of dream about which there is little doubt. The occurrence of these dreams does not in any way settle the above issue since these dreams are very infrequent, and characteristically are unique in both form, coloration, and the quality of the subjective reaction of the dreamer during and after dreaming.