13 - 18 OCTOBER 2013, ATLANTA, GEORGIA, USA

Hierarchical Qualitative Color Palettes

Contributors: 
Martijn Tennekes, Edwin de Jonge
Description
Color is an important means to display categorical data in statistical graphics. Categories are often hierarchically structured in a classification tree, but most qualitative color palettes do not take this hierarchy into account. We present a method to map tree structures to colors from the Hue-Chroma-Luminance (HCL) color model. The HCL color space is known for its well balanced perceptual properties. Our study suggest that hierarchical qualitative color palettes are very useful: not only for improving standard hierarchical visualizations such as trees and treemaps, but also for showing tree structure in non-hierarchical visualizations.