How to change preview colors?

I loaded my customized visual theme (copy of the source Dark.css file) but was not able to change colors of the preview textarea to match the dark theme of the rest of the GUI. And to remove this dazzling blob from an otherwise dark workspace.

image

In the CSS file there is:

#previewBody {
    background-color: #272b38; /* -fx-control-inner-background*/
    color: #7d8591; /* -fx-mid-text-color*/
}

but changing the colors or the font has no effect.
Any idea?
Thanks!
mario

I suspect the problem is in file: jabref-master\src\main\java\org\jabref\gui\preview\PreviewViewer.java where I don’t see any reference to theme in JS_HIGHLIGHT_FUNCTION definition or in setPreviewText() function.
I think it is better to move this topic to a GitHub issue.(#7068)

The bug has been fixed in the latest development version.