How to use the color palette tool
As soon as we imported the data for our choropleth map and got to step 3: "Visualize" in the map creation process, Datawrapper lets us choose a color palette for our map:
This simple tool is powerful. The colors we choose have a huge impact on our map: How it is perceived, how well our statement is communicated, and how honest we present the data. The following article explains how to use the color palette and what the different options mean for our map design.
This article won't explain the "Interpolation" part of the feature. If you want to read up more on what interpolation means and when to use which kind of interpolation, please visit the article "How to choose stops for choropleth maps".
This article focuses on continuous color scales. To learn how to define the colors for a stepped color scale, please visit the article "How to customize stepped map colors".
Sequential & diverging color palettes
When we click on the color gradient, we choose other color palettes than the one that is selected by default. We can choose between six sequential color palettes (at the top) and three diverging color palettes (at the bottom).
Sequential color palettes are great when our numbers go from low to high, like unemployment data, life expectancy or birth dates. These palettes often have bright colors on one side and dark colors or a completely different color on the other side of the scale. Bright colors represent the low values while dark colors represent the high values.
Diverging color palettes can be used when both extremes and the middle point of our scale are interesting for our map. We can use it for social studies or show how our regions compare to an average value (e.g. "Countries that are more and less religious than the world average"). We can also use it for elections, especially in two-party-countries like the US: Each side of the palette can represent one party.
Change the colors of color markers
We can create our own color palette by changing the colors of the color markers. To do so, click on the little wrench icon next to the gradient. A gradient with markers will appear. Click on the marker and a color picker will appear:
Add & delete color markers
If we want to add color markers, click on some free space next to a color marker that already exist. The new color marker will automatically take the color of the color palette where you place the marker. Meaning, your map won't change if you just add new color markers (and don't drag them or change their color).
To delete color markers, we can drag them up, away from the color bar. In contrast to adding color markers, that will often change the color of the gradient:
Move color markers
We can drag the color markers around to change with which color values are shown on our map. Note that this will change the massively how your data appears on a map. When people say that "it's easy to lie with maps", that's what they mean. Please don't use this to manipulate the map to your liking.
Fix the lightness of your gradient
Every sequential gradient should move from a light to a dark color consistently. Meaning, the color should become darker in even steps.
However, if you play around with the markers, it's easy to mess up these even steps. That's why we offer a Autocorrect lightness button. Use it often, to make sure your gradient works well.
For this feature to work, our software needs to recognize a lightness gradient. If you set colors that are too dark in the bright part of the gradient or the other way round, the button will be greyed out.
Increase or decrease contrast
If you want to make it easier fo your readers to recognize little differences between colors, try to increase the contrast. You'll find that your brightest color becomes brighter (close to white) and your darkest color becomes darker.
Since the contrast between white and black is the highest contrast there is, decreasing and increasing the colors often will lead to a greyscale gradient.
Importing and exporting colors
Datawrapper gives you the option to import and export color palettes as a list of hex codes. That's useful for several reasons:
- import color palettes from other tools, like from the Chroma JS Color Scale Helper, ColorBrewer or from this Carto site.
- prepare several maps who will all have the same color palette
To use this feature, click on Import Colors, then paste a list of hex codes. Or click on Export Colors to copy the hex codes that your color palette uses right now.
In case your color scale is "the wrong way round", simply reverse it. That's especially useful for diverging maps: e.g. if we want to show low values with the red color of the US-Republicans and the high values with a Democratic-blue. Since Datawrapper doesn't know that, our colors might be exactly reversed when we choose the red-blue color palette. A click on "Colors" and then "Reverse" will help.