About the observation of colour
- The human eye is sensitive to the visible spectrum, which includes all the spectral colours ranging from approximately 400 to 700 nanometers.
- The sensitivity of the eye to the visible spectrum enables us to perceive colours when light interacts with objects.
- The visual perception of colour by an observer is associated with words such as red, blue, yellow, etc., which are commonly used to describe hue or dominant wavelength.
- The colour an observer sees depends on:
- The wavelengths of visible light present in the environment.
- The wavelengths absorbed, transmitted, or reflected by an object or medium.
- The perception of colour can be affected by factors such as brightness, contrast, and saturation, which are related to the amount of light present in a stimulus and its interaction with the eye and brain.
- The observed colour of light is determined by its wavelength, not its frequency. However, as light travels from one medium to another, such as from air to glass, the colour seen by an observer may change due to refraction causing colours to disperse in different directions.