A11ying with Sanna - Web Content Accessibility Guidelines a guide to the accessibility requirements
1 Perceivable

1.4 Distinguishable

Make it easier for users to see and hear content including separating foreground from background.

1.4.1 Use of Color

Conformance level: A

Do not use color as the only visual means of conveying information.

1.4.2 Audio Control

Conformance level: A

Provide a mechanism to stop, pause, or control the volume of audio that plays automatically.

1.4.3 Contrast (Minimum)

Conformance level: AA

Ensure sufficient contrast between text and background.

1.4.4 Resize Text

Conformance level: AA

Allow text to be resized up to 200% without loss of content or functionality.

1.4.5 Images of Text

Conformance level: AA

Use text instead of images of text.

1.4.6 Contrast (Enhanced)

Conformance level: AAA

Provide a higher contrast ratio for text and images of text.

1.4.7 Low or No Background Audio

Conformance level: AAA

Ensure that audio content has no or low background noise.

1.4.8 Visual Presentation

Conformance level: AAA

Offer users the ability to control foreground and background colors, line spacing, and width of blocks of text.

1.4.9 Images of Text (No Exception)

Conformance level: AAA

Avoid images of text in all circumstances.

1.4.10 Reflow

Conformance level: AA

Ensure content reflows to fit a viewport without requiring horizontal scrolling.

1.4.11 Non-text Contrast

Conformance level: AA

Ensure sufficient contrast for user interface components and graphical objects.

1.4.12 Text Spacing

Conformance level: AA

Ensure content is readable and operable when users adjust spacing.

1.4.13 Content on Hover or Focus

Conformance level: AA

Ensure that additional content triggered by hover or focus is dismissible, hoverable, and persistent.