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.
Parts
- Mark — The core mark of Color systems is hue, value and chroma mapped to category or magnitude.
- Scale — The scale must show zero (or a declared break) and units.
- Axis — Axis titles name the variable, not a mood.
- Legend — A legend is weaker than a direct label. Write beside the mark when you can.
- Label — Numbers are optional. If comparison is the job, label the ends only.
- Grid — Keep the grid faint. Data should own the ink.
- Annotation — One annotation sentence. Date the source.
- Frame — A thin frame. Never a 3-D box.
Variants
- Palette — Variant 1 of Color systems. Same encoding, different layout.
- Brand colors — Variant 2 of Color systems. Same encoding, different layout.
- Sequential scale — Variant 3 of Color systems. Same encoding, different layout.
- Color systems 4 — Variant 4 of Color systems. Same encoding, different layout.
Labels
- Axis — On Color systems, make Mark readable.
- Legend — On Color systems, make Scale readable.
- Label — On Color systems, make Axis readable.
- Grid — On Color systems, make Legend readable.
- Annotation — On Color systems, make Label readable.
Color systems: honour hue, value and chroma mapped to category or magnitude, and switch when rainbow defaults, or encoding two quantities in one hue.