If you set the following css:

.root {
    -fx-base: rgb(30, 30, 30);
    -fx-background: rgb(30, 30, 30);
    -fx-control-inner-background: rgb(30, 30, 30);
}

Labels and other texts within UI controls are still rendered black instead of white. This has worked with 2.0.2. 2.1 Beta 10 has a slight improvement over beta 9: The menu now is rendered correctly, but many texts are rendered black instead of white, see screenshot.