Style switcher papercut
Found a quirk in the recent style switcher changes. It seems that the mechanism used to generate the previews now only accepts the exact styles it requested. If the style is missing, it won't use a fallback style, it will just use the default text color instead.
I don't know if there's something needs to be done on the Text Editor/GtkSourceView side or if it just works as expected, for now I prepared a MR that adds all the missing styles to the default style schemes so it would work properly regardless. Before/after: