The difference between at least two colour tones is called colour contrast. Colour contrast is elementary for visual perception. We can see objects by separating them from their surroundings. For this reason, colour contrast should also be taken into account in lighting design for architecture. The contrast between body colours or light intensities can emphasise areas in (interior) design. On a white background, in addition to coloured light, the light colours of different shades of white – ranging from a reddish warm white and neutral white to a bluish cool white – are a design tool in lighting design.