It is impractical to edit the settings when using a dark GTK theme

[luisfpg]

The settings page use a fixed light color for the background, but doesn't set a fixed dark foreground color. Hence, if the system defines the font color to be light, it is hard to see the text over the light background. The solution would be to either follow the system theme in both or in none of foreground and background colors. See the screenshot using KDE's Breeze Dark theme:

[scmanjarrez]

A workaround is to switch between tabs, then you get the dark background. At least it works for me.