Color and accessibility in underground wayfinding and signage design,

Color is one of the most influential assets in the language of visual design. It is often used to emphasize, differentiate or to connotate graphic messages in many different contexts from brand to interface design. Many of our interactions with the physical or digital environment surrounding us are mediated by chromatic information. Although color blindness is not explicitly considered a physical impairment, it could be, therefore, a limitation in everyday life. In particular, many of the signage and wayfinding system, such as traffic light, street signs, and so on are mainly based on the color codex. Moreover, in undergrounds maps, wayfinding scheme, archigraphy, brand, and signage plans and artifacts make broad use of color language. The paper presents and discusses this issues according to the Universal design/Design 4 all principles from a theoretical point of view. Then, research maps and exemplifies some of the most relevant case studies in the history of underground signage design from the London Tube to the Porto project. In the end, the article proposes and debate the best practice and guideline of inclusive color signage design strategies.