Comment 118 for bug 220263

Evan, what that patch will not do is fix the input field issue on explicitly chosen dark themes. What I would recommend instead is simply making this bit of userContent.css equivalent completely override Gtk regardless of theme, to produce the desired output:

INPUT, TEXTAREA {color: black ; background: #ffffff ; }

This is the general case which websites expect, and which users expect, and in my testing does not interfere with sites that explicitly set up a different color combination for text input areas. I don't even think it's -possible- to recreate this bug on the Windows or Mac ports without manually messing with userContent.css, so forcibly overriding Gtk here seems like the intelligent thing to do.