The terms brightness and colour brightness have distinct meanings. The first refers to a property of light, and the second to a property of colour as detailed below.
- Brightness (as opposed to colour brightness) is used to refer to a property of light.
- Colour brightness is used to refer to how much colour something appears to emit or reflect towards an observer.
- Colour brightness can be understood as the variation in how a colour is perceived by an observer under well-lit conditions compared to its more muted appearance when in shadow or under poor illumination.
- Colour is what humans see in the presence of radiated or reflected light.
- The brightness of the colour of an object or surface depends on the intensity of the incident light, as well as the wavelengths of light the object absorbs and reflects.
- The colour brightness of a transparent or translucent medium may depend on the intensity of the incident light, the wavelengths of light it absorbs and transmits and the amount it reflects.
- Colour brightness can differ depending on the difference between the way a colour appears to an observer in well-lit conditions compared with its subdued appearance when in shadow or when poorly illuminated.
- The perception of colour brightness can be influenced by hue, as some hues, such as fully saturated yellow, can appear brighter to human observers than others, like fully saturated red or blue.