This question already has an answer here:
Since a couple of years, I have the dark desktop theme by default. Since I upgraded to Ubuntu Gnome 16.04 a week ago, firefox upgraded with it, and it now uses a dark theme as well. That's okay with me, except for the fact that a fair number of web forms now have become unreadable: the text is white, but the form fields are white as well, so you can't see what you're typing.
Workaround: select the text after you've typed it, then it becomes visible and you can inspect it.
Other workaround: type everything in gedit and copy-paste it from there.
Sure, there are workarounds, but this is very annoying. I like the dark theme so I prefer to keep using it, but for web forms it's just not a good idea.
Is it possible to keep the dark theme but fix its behavior in web forms such that they are always readable?