General guidelines

• Don’t make your chart too colorful; fewer colors generally improves clarity for your reader. (example)
• Every palette has 4 variations, try to only use the first row (palettes D1, S1, or Q1).
• You can make use of additional colors in between specified colors where needed. In Stata for example you can make use of ‘ipolate’ (interpolate) to generate additional steps. A good guide on using this can be found here.

File type

Always export your graphs in vector formats such as .svg, .eps or .ai files. If you use an application or platform that only exports in .jpg or .png please consider using alternatives.

If you need any assistance or clarification, please contact Niek.

When to use Qualitative, Diverging or Sequential palettes?

Qualitative

A qualitative palette is used when the variable is categorical in nature. Categorical variables are those that take on distinct labels without inherent ordering. Examples include country or state, race, and gender. Each possible value of the variable is assigned one color from a qualitative palette. (for more information & examples see these articles: Chartio.com & Datawrapper.de)

Sequential

When the variable assigned to be colored is numeric or has inherently ordered values, then it can be depicted with a sequential palette. Use a sequential color palette if the main reason for the graph is to emphasize the highest values. If your graph is about the lowest and highest values, use a diverging palette.

Diverging

If there’s a meaningful middle value, use diverging colors. That could be:

• zero, e.g., positive and negative economic growth
• 50%, e.g., the vote between two choices
• the average or median, e.g., age below and above the median age
• an agreed threshold, e.g., income levels below and above the poverty line
• a target, e.g., revenue below and above the quarterly target

Please refer to this article for more information on when and how to use Sequential, Diverging and Qualitative palettes.