UI Patterns
Data Visualization
Charts and graphs need a text alternative — a short summary, a data table, or both. Don't tell data series apart by color alone; add labels, patterns, or direct annotations. Bars, lines, and segments must meet 3:1 non-text contrast.
In plain terms
Charts need a written summary or a data table, and shouldn't rely on color alone, so people who can't see them still get the message.
Why this matters
A chart that carries its message through shape and color alone is meaningless to blind users and hard for color-blind users. They need the underlying numbers and labels in another form.
How to detect
Quick check
For each chart, check for a text summary of the takeaway and/or an associated data table. View it in grayscale — can you still tell the series apart without color?