Colors are used in warning messages in combination with signal words to attract the attention of users and to communicate to them the risk in using a product. Little attention has been paid to the effectiveness of color as a signal. Standards for the colors to be associated with different levels of hazards have not been based on empirical study. The experiments using semantic differential and free-association techniques reported here obtained responses from 261 college students regarding the relative effects of colors as signals of risk. The use of signal colors in the combinations suggested by various standards organizations was not well supported by the data. Suggestions for alternative approaches were made. These include use of shape components as part of the signal and the necessity for training of individuals in the nature of warning signals. Relevance to industry
Industry often involves hazards requiring warnings. Signal words and colors are used to alert individuals to the hazard's severity. Correspondence of colors to the signal words and to the severity of the hazard should be that used by those individuals affected. Because this may not happen additional efforts are needed.