Which background to use for text style previews?

So I thought I am smart and made a patch to have the text style selector in the text shape configuration of Calligra always with a white background.
Because in the text style selector the names of all styles are rendered as a preview, incl. the color. Which is nice, but is flawed with dark UI color schemes, as typically text styles have dark colors, so the name is hardly seen. And as the preview in the style manager is already done on a white background, and the sheet of a new blank document is white… well, I thought it is smart to just fix the text style selectors to always have a white background.

Just… I already saw it before because one of the testing documents had a, exactly, white text style, as that was for a colored header. And since then there is more and more of that kind jumping into my eyes… e.g. here in Calligra Stage:

Sigh…

What could be done about this?
The initial idea was to always use the background of the currently selected shape/page. But what if that is a gradient, then use the color under the cursor? That could result in an ever changing UI, not sure that is preferred. And would not work for the style manager, where one background color has to work for all text styles, both in the listview as in the big preview area.
Faking a transparent background, the usual way with a check pattern? That looks ugly, no?