This map does not depict actual data. Instead, it has been carefully designed to be a diagnostic tool for evaluating the robustness of individual color schemes. Full use of this tool will benefit your map designs because colors (even very similar colors) are easy to differentiate when they appear in a nicely ordered sequence (such as a legend). The task of differentiating the colors, however, becomes much harder when the patterns on the map are complex, such as in the lower left corner of the diagnostic map.