5 Stars. This add-on is the best option in Firefox Quantum for correcting the flawed design of websites that feature barely visible grey text. An alternate add-on with the same objective exists, but it is quite buggy in post-57 Firefox.

The introduction of the blacklist feature in version 1.3.1 further cements Font Contrast as the best add-on of its kind. Thanks to the developer for the response to my previous review, in which I had requested this feature.

With regard to the comment by Joy, below:

The icon in the address bar can be hidden (right-click it and select appropriately). Thereafter, right-click the Firefox titlebar, select "Customize..." and drag the Font Contrast icon among your other add-ons. If you ever restart your Firefox with add-ons disabled, you'll have to redo the part about hiding the address bar icon, as doing so will restore the icon. Ultimately, though, what you want is easily done.