I have been using the Manjaro i3wm in 2-3 different machines. Lately, and seems more prevalent in the latest kernel on my laptop that every once in a while, particularly in Palemoon browser, but also in some other applications, I am unable to read the text I type into some of the dark theme entry boxes. The text colour is very dark grey to almost black. On other apps the same theme of box produces a nice white text so I can actually see what I am typing.
I have been unable to determine any consistency and I have not been mucking around with any theming.
I see, but I thought you could see what will happen, if it could be a problem with just your theme and palemoon. I rember sometimes in the past I had to set something for firefox to use the same (gtk-)theme as the system or another theme because it didn’t work with my favourit theme then. Maybe your problem is similiar. If you look sharp, palemoon is nothing more than a very old firefox.