Sources

Annotated bibliography. All sources were consulted directly in July 2026 except where noted. Hex codes in 03-color-palettes.qmd trace to the starred (★) primary sources.

1 The three newsrooms

1.1 Financial Times

• ★ Visual Vocabulary — Financial-Times/chart-doctor, visual-vocabulary/, https://github.com/Financial-Times/chart-doctor/tree/main/visual-vocabulary. The normative chart-type taxonomy in 02-chart-types.qmd: nine analytical functions (deviation, correlation, ranking, distribution, change over time, magnitude, part-to-whole, spatial, flow) with per-chart usage notes. Interactive version: https://ft-interactive.github.io/visual-vocabulary/.
• ★ g-chartcolour — ft-interactive, https://github.com/ft-interactive/g-chartcolour, docs https://ft-interactive.github.io/g-chartcolour/. FT chart color tokens: paper #FFF1E5, web line palette, sequential/diverging ramps, political palettes.
• Origami o-colors — https://github.com/Financial-Times/o-colors (archived; now in https://github.com/Financial-Times/origami). Brand palette Sass tokens.

1.2 BBC

• ★ BBC Visual & Data Journalism cookbook for R graphics — https://bbc.github.io/rcookbook/ (source: https://github.com/bbc/rcookbook). Working hex codes (#1380A1, #FAAB18, #990000, #588300; neutrals #333333, #CBCBCB, #DDDDDD), gridline/legend/baseline rules, chart types demonstrated, annotation conventions.
• ★ bbplot — https://github.com/bbc/bbplot. bbc_style() theme and finalise_plot(): left-aligned title block, source bottom-left, logo bottom-right, 640×450 px default export.

1.3 The Economist

• ★ The Economist visual styleguide (chart style guide PDF, 2017-05-05). Mirror consulted: https://sa.ipaa.org.au/wp-content/uploads/2026/02/Economist-CHARTstyleguide_20170505.pdf. Web chart palette (Econ red #E3120B, blue #006BA2, cyan #3EBCD2, …; black #0C0C0C, text #3F5661), equal-lightness color scales, standard color order and overrides, pie limit (“abandoned in favour of stacked bar if over 4 categories”), double-scale rules (no broken scales, aligned zero lines, no disparate measures; else panels or indexing).
• “Mistakes, we’ve drawn a few” — Sarah Leo, The Economist (Medium, 2019), https://medium.economist.com/mistakes-weve-drawn-a-few-8cdd8a42d368. Self-audit of misleading practices (truncated axes, forced dual-scale correlations). Not fetchable at time of writing; cited from the styleguide’s matching rules.

2 Corroborating authorities

• ★ UK Government Analysis Function — Data visualisation: charts, https://analysisfunction.civilservice.gov.uk/policy-store/data-visualisation-charts/, and Data visualisation: colours, https://analysisfunction.civilservice.gov.uk/policy-store/data-visualisation-colours-in-charts/. Accessible categorical palette (#12436D, #28A197, #801650, #F46A25, #3D3D3D, #A285D1 — all ≥3:1 on white), sequential blues, focus palette (#12436D + #BFBFBF), and the do/don’t list (≤4 lines, ≤4 bars per cluster, never break bar axes, horizontal text, direct labels, ≤10 gridlines, pie rules, SVG output). Implementations: afcharts (R), py_af_colours (Python).
• ★ Okabe, M. & Ito, K. — Color Universal Design: How to make figures and presentations that are friendly to colorblind people, https://jfly.uni-koeln.de/color/. The 8-color colorblind-safe palette and the redundancy principles (shape/line-type pairing, vermilion over red). Also shipped in R as grDevices::palette.colors(palette = "Okabe-Ito").
• ★ Urban Institute Data Visualization Style Guide — https://urbaninstitute.github.io/graphics-styleguide/. Typography scale, palette structure, the “absolutes” (no dual axes, zero baselines for bars, pie ≤5 slices, ≤7 categories, no 3-D), alt-text practice (~160 characters).
• Datawrapper — Lisa Charlotte Muth, A detailed guide to colors in data vis style guides, https://www.datawrapper.de/blog/colors-for-data-vis-style-guides. Palette-construction guidance: data vs non-data greys, lightness range (60+ points), semantic category colors, size-dependent saturation, brand-color discipline, and the newsroom comparisons cited in 03.
• W3C, WCAG 2.2 — https://www.w3.org/TR/WCAG22/. Criteria applied: 1.1.1 (non-text content), 1.4.1 (use of color), 1.4.3 (text contrast 4.5:1), 1.4.5 (images of text), 1.4.11 (non-text contrast 3:1).
• ColorBrewer — Cynthia Brewer, https://colorbrewer2.org/. Tested sequential and diverging schemes referenced for diverging defaults.
• viridis — perceptually uniform, colorblind-safe continuous scales; in ggplot2 as scale_*_viridis_*(). https://sjmgarnier.github.io/viridis/.

3 Verification notes

• Contrast ratios quoted in 03 and 05 were computed from the cited hex codes with the WCAG 2.x relative-luminance formula (not copied from the sources): Analysis Function categorical palette 3.03–10.86:1 vs white; Okabe–Ito yellow 1.32:1, orange 2.25:1, sky blue 2.31:1 vs white (hence the caveat in 03); BBC #333333 text 12.63:1.
• The Economist hex values were extracted from the styleguide PDF’s own text layer; where third-party summaries disagreed with the PDF, the PDF was used.