Default Excel colours — that bright primary palette that screams 'made in 2003' — are why corporate slide decks look corporate. The palette communicates 'I used what was on the menu' instead of 'I chose this'. Choosing well doesn't require design talent; it requires knowing the rules.
Three palettes for three data types
- Sequential: for ordered data where bigger means more (or less). Single hue, varying lightness. Blues for cool, oranges for warm. Use ColorBrewer's Blues, Oranges, or Greys.
- Diverging: for data with a meaningful middle point (zero, baseline, average). Two-hue palette running from one colour through white to another. Red-white-blue for political; blue-white-orange for neutral analyst use.
- Qualitative: for unordered categories (regions, products, segments). Use distinct hues with similar perceived intensity. ColorBrewer's Set2 or Dark2 are the analyst standards.
Four colour mistakes
(1) Using a qualitative palette for ordered data — order is lost. (2) Rainbow palettes (red→orange→yellow→green→blue) — perceptually uneven; the human eye reads red as 'higher' regardless of where it sits. (3) Pure saturated colours for background or non-data elements — they fight with the data for attention. (4) Encoding two variables in colour and shape simultaneously without showing it works for colour-blind readers (8% of men). Test with the Color Oracle browser extension.
Grey is the default
The most underused colour in analyst work is grey. Most chart elements — gridlines, axis labels, secondary data series — should be grey. The line you want the reader to look at should be one bold colour against a sea of grey. The FT graphics desk calls this 'the highlight discipline'. Try it once; you'll never go back.
BEFORE: 5 lines, 5 different bright colours, no hierarchyAFTER: 5 lines — 4 in light grey, 1 in dark amber (the one you're talking about)Reader's attention: immediately on the amber line.
Typography hierarchy
A publication-grade chart has at least three text sizes. The action title is the largest and boldest. The deck (sub-title) is medium and lighter. Axis labels and tick marks are smallest. Annotations match axis size but in the accent colour. Source notes at the bottom in the smallest size, near-grey.
The WSJ chart anatomy
Top to bottom on any Wall Street Journal chart: (1) Bold action title (~16pt). (2) Lighter deck explaining the metric or time period (~11pt). (3) Chart proper. (4) Inline annotation in accent colour. (5) Axis labels (~9pt grey). (6) Source line (~8pt italic grey). The hierarchy is the same on every chart, which is why their pages read consistently.
Exercise
Find a chart you've made. Identify each text element. Are there at least three distinct text styles? Is the title the largest? Is the source attribution visible but quiet? Redraw with explicit hierarchy and a single accent colour for the line or bar you want the reader to focus on.