Color in visualizations

Improving Your Data Visualizations in Python

Nick Strayer

Instructor

How color is used

Differentiates classes of data
Encodes continuous values
Should be used carefully

colorful ribbon

Color can be beautiful

Boring → eye-catching
Variety is good

start greyscale map compared to colorful blue map

Meaning is often applied to colors via culture/ personal experience

¹ Parlapiano, A. (2016 November 1) There are many ways to map election results. We've tried most of them. New York Times. Retrieved from https://www.nytimes.com/

Bar chart showing how color preferences vary

Color can be misleading...

"It is evident that the color-size illusion is present in a marked degree [no matter what] arrangement."

C.J. Warden & E.L. Flynn, 1926

Cartons of varying sizes and colors

A remedy for the color-size illusion

sns.barplot(x = values, y = ids)

rainbow colored bar chart with no borders

sns.barplot(x = values, y = ids, 
            edgecolor = 'black')

raibow colored bars with black outlining bars

sns.barplot(x = values, y = ids, color = 'cadetblue')

bar chart with all blue bars

Let's paint some data!

Improving Your Data Visualizations in Python