Three Tips for Choosing the Colors for Data Visualization
Colors can add to your data visualization and make the story stand out or they can distract the audience from the main message. It all depends on what colors you chose and how you use them. In this post, I am listing three things to keep in mind when creating your next data visualization. I am not guiding you specifically on what colors (hue, value and chroma) to use but three things to keep in mind when selecting the colors:
- Use conventional colors: Generally red color means negative or a bad value and green means positive or a good value. Choosing the default colors as presented by your visualization tool might not convey this meaning in all the cases. Say, for example in Tableau, when you choose the default “Red-Green Diverging” color from the pallet, the red represents the smallest number while green represents the largest number, and it changes from red to green for the values in between. This generally works fine. Where this becomes an issue is when smaller numbers are actually better than the larger numbers. For example, when you are showing Cost Per Click, lower is better so it should be Green while higher numbers are bad, hence they should be Red. Leaving the default will show low CPC as red, while higher CPC will be green, this will convey the wrong message to someone who is just glancing at the visual. To fix this issue in this case, all you have to do is just check the box, titled “Reversed” to reverse the colors, now Red will be used for higher value.
- Don’t use too many colors: Using too many colors can distract the consumer of the visualization from the main message. Minimize the number of colors you use in your visualization. (See guidelines for selecting colors section in “Expert Color Choices for Presenting Data” paper by Maureen Stone)
- Make main message/data to stand out: Make sure the color combinations you chose enables you to make the main message to stand out. For example, white on black will stand out while grey on black might be lost.