Text doesn't have enough contrast against its background
Light grey text on white, or text over photos, is hard or impossible to read for people with low vision or color blindness, and for anyone outdoors on a phone.
Who it affects
Makes a task significantly harder (low contrast, links with no name, missing frame titles).
First fix
Use a darker text color or lighter background so the contrast ratio is at least 4.5:1 (3:1 for large text).
