Text should provide enough contrast with its background so that it can be read easily by people with moderately low vision, including colorblind people.
This rule raises an issue when a CSS selector defines both the ``++background-color++`` and ``++color++`` properties with a contrast ratio of less than 4.5:1, which is the contrast required to meet WCAG AA level. It applies only when the selector is not on a heading (``++h1++``, ``++h2++``,...) or ``++title++``
