What each colour in a page is actually for.
A page's accent marks what can be clicked, and an underline carries the same meaning for a reader who does not see the hue. Both cues together is what the intact case looks like, and either one on its own would be enough.
A second sentence with another link inside it so the rule has more than one element to read on this page.
Panels sit on the base, and their own boundary is a mark.
Muted ink for what supports the sentence above it.