The role of color in data visualization is huge. It's one of the early markers that help to convey a story. Yet, few articles or research studies focus on the role of color in data storytelling.
Let's look at some examples of different ways of using color in data visualization and the role that color plays in data storytelling.
Sunny, hopeful yellow in the data visualization by Oksana.
This visualization tells the story of inequality in the education system of the United States. It was developed for a nonprofit called Donors Choose. They provide books, and educational materials, to children in need of them, and essentially try to bridge the gap between children from wealthy families and poor families.
An alerting, dangerous red in this visualization for the same cause by Simone Betito.
Oksana and Simone used the same dataset to create their visualizations. They chosen similar data visualization types. Yet, their visualizations make very different first impressions.
When you see a color theme in a data visualization, it affects your experience of viewing it, even if you don't realize it.
Different roles of color in data visualization
So let's talk about some ways you can use color to deepen your narrative.
1. Color simplifies complex stories
Different tones can help viewers follow stories that jump between different categories and topics.
In this visualization, Angie Chen has used color to show different micronutrient deficiencies. Different color intensity is used to show the level of deficiency, and although she uses the same visualization type (map) several times in the row, it doesn't look repetitive. It helps the viewer and guides the eye.
Here is another way of using color for the same purpose. Kizley Benedict is using the contrast of blue and orange to tell two different stories. But these stories are intricately correlated, and so it makes sense to have them both on the same visual.
2. Color makes the viewer feel
Light and color are deeply connected to emotion. When the colors are dull and grey, they communicate a sense of calmness and uniformity. And so grey was a common theme of the data visualizations that were created for a nonprofit called Open Sourcing Mental Illness. This nonprofit works to promote awareness about mental health in the workplace and helps companies become more inclusive regarding employees with mental health issues.
Greys map out all the context, so the reds look even more alarming. They work as a visual punch and amplify the important facts.
3. Color can communicate ideas
Color can reveal meaning. When a color repeats, it communicates the same idea.