In Subtleties of Color, Robert Simmon discusses the importance of color to show patterns and relationships that are otherwise hidden in a mass of numbers. He emphasizes how color is a tool to make visualizations more intuitive and successful. Throughout the series, Simmon discusses several types of data (sequential, divergent, and qualitative) and the colors suited to their different types of display. For instance, sequential data is best represented by color palettes that vary evenly from light to dark, divergent data is suited to a palette that uses two different hues that vary from a central neutral color, and qualitative color uses color to separate areas into distinct categories. I also look forward to incorporating Simmon's tips on layering multiple data sets in my future work. He describes the approach of using muted colors to limit the contrast and hues in one data set, and then overlaying the other data set. The color schemes for datasets displayed together should be designed together, and complement one another.
Another interesting topic was that of connecting color to meaning and how it evokes an emotional response in the audience. His example of Iraq’s Bloody Toll vs. Iraq: Deaths on the Decline charts show how by flipping the orientation and changing the color from red to blue, the graph is given an entirely different message.
Simmon discusses how colors have emotional and socially constructed meanings, some of which are unique to specific cultures. This point made me think of all the colors within my cultures that have different meanings and uses than they do here in the US.
In addition to how color enhances data sets, Simmon also discusses the issues that complicate color choices in visualization. One of the most interesting topics was with presentation and accessibility issues and how the use of red or green can make specific visualizations more difficult to differentiate. I agree that in order for a visualization to be most successful, it should be readable for the largest audience possible.