Maps in shades of grey

A wheel of all the colours of the rainbowWhat does a map look like if you have a colour-blindness condition? Colour Vison Deficiency (CVD) is more common than most people think, and it’s not just red and green. Where colour is used to provide information, some people can be left confused. Directional maps, such as street maps for example, use colour to indicate train stations and heritage sites. Geographical maps use colour to show height of land, temperature, and to separate land from water. Many of these are age-old conventions that designers follow. So how do you know what colours are best to use? The Colblinder website give examples of what geographic maps look like to people with CVD. It also has links to other references and a colour blindness simulation tool. Although this is about maps, it can also apply to websites and printed documents, such as guidelines, and manuals where pictures and graphics are used to inform and instruct.

For the latest research on this topic Anne Kristin Kvitle’s article is worth a read. The article is titled, “Accessible maps for the color vision deficient observers: past and present knowledge and future possibilities”. Here is the abstract:

“Color is one of the most difficult cartographic elements to use, as it easily draws attention away from the data and goals for the map when it is used poorly (Krygier and Wood 2011). It is also the one cartographic element that is most frequent misused. Some conventions are choosing colors that have a similarity to real life objects, like green and blue to represent land and water. Other conventions are to use strong colors to emphasize important objects, like the use of red to represent highways or cities. One major contribution to the art of cartography is the development of the visual variables proposed by Jacques Bertin (Bertin 1983). These graphic elements (i.e. position, size, color, orientation, shape, value, texture) were designed to utilize graphic information representation, and have been adapted as a language of cartography.