Task-based color scale design

Color is commonly used in data visualization in order to convey a wide variety of types of information: metric values, pattern, extrema, emphasis, and others. A distressingly large percentage of these visualizations appear to use the default color scale for the visualization package used to create them. While sometimes this is an appropriate choice, careful consideration of the implications of color scale selection can often result in a more effective visualization. Factors which should be considered include the characteristics of the data, the questions of interest about the data, and the expected viewers of the representation.