The default color space for computers includes over 16 million colors—an embarrassment of riches that is also a potential quagmire to anyone considering how to best choose colors for visualizations. In this workshop, we will provide a practical framework for working with color. We will start by developing an understanding of color models and color theory, building from these to provide simple but powerful heuristics for color selection that will enable creators of data visualization to enhance the clarity, power, and storytelling of their visualizations. We will conclude with the introduction of tools for working with and selecting color, followed by hands-on activities using these tools. No prior knowledge is needed or assumed, and the only tools you will need is a computer with a web browser and an internet connection.