Color systems encodes values as hue, value and chroma mapped to category or magnitude. Munsell 1905; Brewer palettes (1994–) for maps; OKLCH in modern CSS.
In reports, ads and assignments it fits legends, brand systems, accessible data color. Skip it when rainbow defaults, or encoding two quantities in one hue.
Software
- Software 1 — Excel or Google Sheets
- Software 2 — PowerPoint
- Software 3 — Figma / Illustrator — ad and poster shapes
- Software 4 — Python matplotlib or R ggplot — assignment and research figures
- Software 5 — This atlas’s server-rendered SVG — examples without a chart library
Exports
- Exports 1 — SVG
- Exports 2 — PDF
- Exports 3 — EMF/SVG into slides (no screenshots)
- Exports 4 — SVG for web, PDF for print
Accessibility
- Accessibility 1 — Never hue alone. Stack pattern, label and position.
- Accessibility 2 — 4.5:1 for text, 3:1 for large marks.
- Accessibility 3 — Short alt text on the chart; numbers also as an HTML table.
- Accessibility 4 — Motion only as emphasis. Honour prefers-reduced-motion.
Color systems: honour hue, value and chroma mapped to category or magnitude, and switch when rainbow defaults, or encoding two quantities in one hue.