Brand Guideline

Data Visualization Palette

A categorical + sequential color palette for charts that stays legible and accessible.

Platform: bothTags: color, data-viz, charts, accessibility, palette

The Rule

Charts use a defined categorical palette (max 6–8 hues, distinguishable by hue AND lightness) for discrete series, and a single-hue sequential ramp for continuous data. Series are also distinguished by a non-color channel (label, pattern, or direct annotation). Semantic colors (red = negative, green = positive) are reserved for meaning, not decoration.

Rationale

Adjacent colors shift each other's appearance (Albers' relativity), so chart colors chosen in isolation fail when placed side by side. Limiting the palette and separating by lightness keeps series distinct for everyone, including color-deficient viewers.

Specifications

categorical6–8 hues max, each also separated by lightness step

sequentialSingle-hue ramp, light→dark, 5–7 stops

divergingTwo-hue ramp through a neutral midpoint for above/below-zero data

contrastEvery series color meets 3:1 against the chart background

Examples

Good: 6 categorical hues that stay distinct in grayscale
Bad: a rainbow of 12 similar-lightness hues where three series look identical