The perception of colour is a highly subjective experience.
Several factors determine the specific colour an observer sees, including:
The environment in which colours are observed, the type of object, and colour associations.
The colour of nearby objects.
Well-being, including health, medications, mood, emotions, or fatigue, can all affect the eyes, vision, and perceptions of an observer.
Different observers may see colour differently because of life experience including educational, social and cultural factors.
The term observer has distinct and different meanings within the fields of special relativity, general relativity, quantum mechanics, thermodynamics and information theory.