“Data visualization is the graphical display of abstract information for two purposes: sense-making (also called data analysis) and communication. … In other words, to visualize data effectively, we must follow design principles that are derived from an understanding of human perception.”
Color value refers to the lightness or darkness of the hue. … Adding black to a hue produces a low-value color, often called a shade. Intensity. Intensity, also called chroma or saturation, refers to the brightness of a color.