The default GTK+3 Breeze theme that improves GTK applications' look under KDE Plasma has some troubles with Firefox. One of this annoying glitches is that the font colour does not have enough contrast with the background, so it is tough to read the tab title.
This theme improves the readability of the tabs titles and uses default colours of the KDE Breeze colour palette, giving a more consistent appearance under KDE Plasma.
