Regulations

Depending on the type of project you are working on, the obligations in relation to visual contrast vary. Currently, the Disability Discrimination Act (DDA) places a duty on employers and service providers to ensure they take 'reasonable' steps to ensure that disabled employees and users of their services / customers are not at a ‘substantial’ disadvantage in comparison to employees or customers who are not disabled.

The DDA does not contain any performance based specification for buildings, facilities or environment. That guidance can be found in The Building Regulations Approved Document Part M, which advises architects and designers working on new build projects or major refurbishments and change of use, to contrast visually adjacent critical surfaces, such as walls, ceilings, doors and floors by selecting colours with a difference in light reflectance value (LRV) of more than 30 points.

For alterations to existing buildings, where Part M may not apply, BS 8300:2001 recommends a minimal contrast of at least 20 points difference in LRV, although a 30 points difference is preferred.

In addition back in 1997, Dulux Trade commissioned Project Rainbow, a research project in conjunction with the University of Reading , the RNIB and Guide Dogs for the Blind. This work focused on understanding how colour contrast can be defined when specifying colours that are frequently used in everyday environments.

It demonstrated how different adjacent colours have to be, in terms of chromaticity, saturation and/or hue, in order to create enough visual contrast for both the visually impaired and fully sighted to notice a discernable difference.

Project Rainbow also identified those critical surfaces that should be considered when developing visually contrasting schemes. By referring to Project Rainbow, architects can aid accessibility but still retain flexibility in design.

This section of the site and the Dulux Trade Colour & Contrast Interactive CD which can be ordered free through the website (see above right), enables architects and designers to more easily design aesthetic colour schemes that have sufficient colour difference on adjacent surfaces – whether based around 20 or 30LRV or Project Rainbow research.

See also

• Colour scheming »
• Visual impairment »