Colorless in a dream signifies a connection to the anxious state of being yourself while other people regard it to be an unconscious desire, stress or being neglected by someone.
In addition, colorless in a dream represents unfinished goals, lack of self-identity or not focusing more on desired possessions.
Overall, colorless dreams are simply lacking in everything. The joy of feeling the warmth of the sun or the cooling of an evening breeze will be hard to come by.