Color for Categories, Not Quantities.
Hue separates 5-8 categories. Use position or length for magnitude.
Hue is effective for distinguishing 5-8 categories but terrible for encoding magnitude. For quantities, use position or length. When color must encode a value, use luminance (light-to-dark) on a single hue, not multiple hues.
Tamara Munzner, 2014 · Visualization Analysis & Design
Charts that apply this principle
100% Stacked Bar
Stacked bar normalized to 100% that compares proportions, not totals.
Donut Chart
A ring chart showing part-to-whole with a hollow center for summary text.
Marimekko Chart
A mosaic of variable-width columns that encodes two dimensions of part-to-whole.
Nightingale Chart
Polar area chart with wedges of equal angle but varying radius, a polar histogram.
Polar Area Chart
Smooth continuous area plotted in polar coordinates. Ideal for cyclic data (24-hour cycles, compass directions, monthly seasonality).
Stacked Area Chart
Layered areas showing how parts of a whole change over time.
Stacked Bar Chart
Bars divided into colored segments showing composition per category.
Waffle Chart
A 10x10 grid of squares, each representing 1%. Intuitive for percentages.
Voronoi Treemap
Partitions space into irregular polygons whose areas represent values, offering an organic alternative to rectangular treemaps.
Mosaic Plot
Categorical × categorical contingency table where both row heights and column widths within each row are proportional to joint frequency.