To avoid breaking the law, you need to keep three key things in mind when publishing any kind of information:
- All headlines/subheads must be marked as H1, H2, H3, etc
- All graphics and images must have descriptive text (aka alt-text)
- There must be a minimum amount of contrast between the colour of text and logos and the background colour.
Contrast checker
To meet AODA standards, there must be a contrast ratio of at least 4.5:1 between foreground (usually text or a graphic/logo) and background.
webaim.org provides quick an easy way to check and adjust colour contrast: https://webaim.org/resources/contrastchecker
To use the checker, arrange your windows so you can see your graphic and the webaim page at the same time:
Accessibility checking in different services or software
Canva has a built-in accessibility checker that will flag contrast failures and missing alt-text.