How to Choose Colors for Data Visualization

Sequential vs Diverging vs Categorical

Data visualization palettes serve a different purpose than brand palettes — they encode meaning. There are three fundamental types. Sequential palettes use a single hue at varying lightness for ordered data (low to high). Diverging palettes use two hues meeting at a neutral midpoint for data deviating from center (profit/loss). Categorical palettes use distinct hues for unrelated categories (departments, product lines). Choosing the wrong type for your data is the most common visualization color mistake.

Choosing Accessible Chart Colors

Accessibility is critical in charts because color is often the primary differentiator. Maintain at least 3:1 contrast between adjacent elements, ensure your palette works under color vision deficiency simulation (avoid red-green as sole differentiator), use patterns or direct labels as secondary encoding, and limit categorical palettes to 6–8 colors (humans can’t reliably distinguish more). For sequential data, single-hue light-to-dark palettes are automatically accessible because lightness is perceived even by users with complete color blindness.

Avoiding Common Visualization Mistakes

Common mistakes: rainbow palettes for sequential data (rainbows are categorical, not ordered), too many categories (15 colors need grouping), brand colors too similar in lightness (indistinguishable in charts), red-green without secondary encoding, and decorative color on data — every color should communicate something. If two bars represent the same thing, they should be the same color. Use the Color Palette Generator to test harmonious chart palettes.

Building a Chart Color System

Build a reusable chart color system: define a 6-color categorical palette where each color has different hue AND lightness, a 5-step sequential palette from your primary color, and a diverging palette for positive/negative data. Test with the Color Blindness Simulator. Store as CSS custom properties or design tokens. Once defined, every chart uses the same palette, creating visual consistency. Update once and all charts update automatically.