mapmaking patterns

Eight percent of men have impaired color vision and will have difficulties distinguishing between colors. Search tasks will be difficult for them when hue is used as the primary distinguishing variable, or when hue is used as a variable for organizing information.

When designing maps that are “universally” accessible, choose unambiguous color combinations, use alternative visual variables (e.g. shape to distinguish kinds of things, size to distinguish quantities of things), and/or directly annotate features.