: In our designed culture, every environment, object and picture is analyzed from the viewpoint of colour and light. Colour and light play an important role in social life and culture. This paper springs from an epistemological project about concept formation in the field of colour and light. Based on own observations and scientific and scholarly references it presents a graphic model describing possible constituent relations between colour and light experiences. Design is the art of using knowledge – implicit or explicit – about how humans perceive, experience, and relate to the world around. In design all senses are involved, but when dealing with colour and light we can confine ourselves to vision; designers must understand the conditions of visual perception. Human experience of colour and light has many sources; the given cultural context (conventional meanings of colour and light), the direct experience of the world around (colour and light expressions) and the basic perceptual functions (formal aspects of colour and light). There is need for distinct concepts and concise approaches to understand coherence of aesthetic and functional expressions. Design education calls for coherent and well defined structures that can be used to describe connections and distinctions between experiences of different kinds.