Effective color usage improves readability and focus:
- Limit colors: Use a maximum of 5-7 colors per chart.
- Highlighting: Use grey for most elements and a single color to highlight the focus.
- Sequential Palettes: Use light-to-dark gradients for magnitude (low to high).
- Diverging Palettes: Use color shifts (e.g., Red $\leftarrow$ Neutral $\rightarrow$ Blue) for positive/negative values.
- Categorical Palettes: Use distinct hues with similar brightness for different groups.
- Colorblind Safety: Avoid red/green combinations; use shapes or labels to supplement color.
- Consistency: Maintain consistent color meanings (e.g., if blue represents revenue, keep it blue throughout the report).
Color Palette Examples (Python)
# Sequential (low to high)
sequential = ["#eff6ff", "#bfdbfe", "#60a5fa", "#2563eb", "#1d4ed8"]
# Diverging (negative to positive)
diverging = ["#ef4444", "#f87171", "#d1d5db", "#34d399", "#10b981"]
# Categorical (distinct groups)
categorical = ["#3b82f6", "#f59e0b", "#10b981", "#8b5cf6", "#ef4444"]
# Colorblind-safe
cb_safe = ["#0077BB", "#33BBEE", "#009988", "#EE7733", "#CC3311"]