Now that we can make some visualizations, let’s talk accessibility to make sure our work reaches everyone who wants to interact with it!
The most commonly discussed accessibility concern is color, since color blindness affects 1 in 12 males and 1 in 200 females. That’s more common than we tend to think! There are a few different types of color blindness: check out the images for simulations of each form.
The big takeaway when designing for color accessibility is to think not only about the hue of a color (e.g. red, green, or purple), but the value as well (e.g. bright red, light green, dark purple). Good color comparisons use high contrast values, not just different hues.
It’s also important to use readable fonts in readable sizes, and make sure they’re web-accessible if online. (If you don’t do this,        will happen!)
Finally, for online data visualizations, make sure to include alt text as we would for any other web image. Alt text ensures that users experiencing a visualization through a screen reader won’t miss out on whatever information it contains.
To recap, here’s a checklist for baseline accessibility:
- Colorblind-friendly color palettes
- Large enough font size
- Readable, web-accessible font type
- Alt text on data visualization images online