Comment 4 for bug 1576042

I'd say the problematic package is Firefox, not oxygen-gtk. Since the former has changed to use GTK3, it might just not be picking all the correct settings. Namely, tooltips text and window text are different things. Windows text color is taken correctly (seen with e.g. Obsidian Coast color scheme), but tooltip text color is not (with Oxygen color scheme), instead appearing the same as window text color.