Data visualization

General guidelines:

Use good color contrast.
- The Color Contrast Analyzer extension for Chrome can check your entire chart in one click. Tip:
  - If using dual monitors, use the external one.
- The Leonardo Scales website can generate high-contrast color pallets. Tips:
  - Choose high-contrast 'Key colors'.
  - Choose the lowest 'Output > quantity' needed for maximum contrast.
Do not exclusively depend on color alone to differentiate between data. People who are color blind will not be able to comprehend it.
- Web Disability Simulator Chrome extension can demo different color blindness experiences.
Label the X and Y axis on charts.
Provide at brief title that summarizes the purpose of the data visualization.
Provide a slightly more detailed caption/summary of the data below the chart.
Most importantly, provide a table that includes the same data that is present in the data visualization. People have a variety of learning preferences. Screen reader users will likely need tabular data for compliant equal access. Some people, even without disabilities, will prefer to view the data in a table.
If you provide equal access via a table, and the image or graphic is not accessible, add alt text that says "Data can be found below" so screen reader users know that they have not been excluded and where they can find the information.
Allow data download when possible.