Visual contrast between floors and adjacent surfaces, fixtures and furniture is important to enable visually impaired people to differentiate between surfaces, identify features and potential hazards such as changes in levels and obstacles on the floor.
A research project undertaken by Reading University in conjunction with the Royal National Institute of Blind People (RNIB), The Guide Dogs for the Blind Association (GDBA) and ICI Paints first examined the use of colour contrast to aid navigation around the building and identified that highlighting critical surfaces and special features can provide the basis for wayfinding for visually impaired people.
The ‘Colour, Contrast & Perception’ document produced by Reading University uses light reflectance values (LRVs) to measure colour and contrast in products/surfaces and determines whether or not a suitable contrast has been achieved between surfaces.
British Standard BS 8300-2:2018 states that light reflectance values are used to assess visual contrast using the method of measurement detailed in BS 8493:2008+A1:2010. Approved Documents K (ADK) and M (ADM) directly refer to colour and contrast in the definitions section, stating:
‘Contrast visually, when used to indicate the visual perception of one element of the building, or fitting within the building, against another means that the difference in light reflectance value between the two surfaces is greater than 30 points.’
All Gradus stair nosing colours have been measured to provide LRVs in order to provide the specifier with the information needed to ensure that suitable visual contrast is achieved with the surrounding stair material. These values have been determined using the CIE Y value, in accordance with BS 8493:2008.