Color charts by data type

Hues for categories, one hue for magnitude, two around gray for +/−.

From refactoring-ui: Data Visualization, “Color in Data Visualization”.

Magnitude wants one hue

Set "See charts as" to Grayscale. Only blue keeps its order.

Five hues as stepsBad
5 hues
One hue, five stepsGood
1 hue × 5 steps

Profit and loss, not red-green

Edit the results, then pick Deuteranopia above.

Red / gray / greenBad
Orange / gray / blueGood

Too many hues blur together

Add categories and watch the closest pair's distance.

One hue per categoryBad
Top four + OtherGood

Why it matters, pros and cons

Why it matters

The palette tells readers the data's structure before any number does. About 1 in 12 men sees red and green as one olive.

Pros

  • One-hue ramps survive grayscale and print.
  • Four hues plus Other stay legible.
  • A gray center marks zero.

Cons

  • Even five hues collide under deuteranopia.
  • "Other" hides the long tail.
  • Trading screens expect red and green; add signs.