It is important that reports are accessible to a wider range of people with disabilities, including blindness and low vision, deafness and hearing loss, learning disabilities, cognitive limitations, limited movement, speech disabilities, photosensitivity and combinations of these.

Web Content Accessibility Guidelines (WCAG) help make web content accessible to people with disabilities. The following are key principles of the guidelines:

• Perceivable. Information and user interface components must be presentable to users in ways they can perceive.
• Operable. User interface components and navigation must be operable.
• Understandable. Information and the operation of user interface must be understandable.
• Robust. Content can be interpreted by a wide range of user agents including assistive technologies.

Microsoft documentation on accessibility

Microsoft provides comprehensive documentation on accessibility in Power BI for authoring accessible reports as well as creating and consuming reports using accessibility tools. 

• Overview of Accessibility.
• Creating accessible reports in Power BI.
• Consuming reports in Power BI with accessibility tools.
• Creating reports in Power BI using accessibility tools.

UMD guidelines on authoring accessible reports

Power BI authors will be expected to follow these guidelines for creating reports that are accessible for all audiences:

• All non-text content has a textual equivalent that serves the same purpose.
• Color is not the only means of conveying information or distinguishing a visible element
• All text and images of text must have sufficient contrast between the text foreground and background
• Reports should be operable with the keyboard and labels of any interactive elements like visualizations, filters, and legends must have titles that are sufficiently clear and self-explanatory to make their operation clear
• Reports include instructions for any interactivity along with descriptive text that explains the information displayed on the dashboard
• Reports support interoperability with assistive technologies such as screen-reading software.

Additionally, formal reports will be QA tested to ensure that these guidelines are followed.

For items that require user configuration, Microsoft's creating accessible reports outlines the necessary steps to modify settings.