I was using "material black" theme, and noticed that the tree does not style properly with it. Its background is shown as white, when it clearly should be dark grey from the theme. Node texts are light grey (set correctly from the theme), so they are barely visible.
The underlying problem seems to be, that kendo.common.min.css has bg color for "div.k-treeview", but kendo.materialblack.min.css doesn't.
Any suggestions, which extra css class we should use for our treeview, without breaking other themes?