For visually impaired people, the colours used in a building can make a big difference in terms of accessibility.
To comply with the Disability Discrimination Act (DDA) of 2005, buildings need to be made accessible to people with disabilities. These include providing for access for wheelchair users and disabled toilets.
Many visually impaired people have some sight and typically can distinguish colours. Research at Reading University found that over 80% of visually impaired people can make out some colour differences.
The DDA guidelines state that key areas should be in a colour that contrasts with the background. Doors, door edges and handrails should be in a colour that stands out from the background colours of the ceilings and walls. Guidelines also state that the minimum light reflective value that provides enough contrast is 30 points.
Sighted people instantly understand the area they enter. Visually impaired people need to pause in order to gather information about the space. If they come from a bright sunny day from outside, they need time for their eyes to adjust to the new luminance. They then walk slowly scanning an area up to about 2 metres away to spot features. A contrasting coloured door is much easier to spot than one painted the same colour as the wall.
Safety signs are colour coded. For example, a red sign says danger or prohibition. Even if a visually impaired person cannot read the text on a sign, the colour tells them that they need to be cautious.