For example, in ubuntu gtk apps has a black toolbar. I'm trying to create a qt app, but QToolbar doesnt use system color(in this case, black). So how can I make QToolBar to use system color? If this is impossible, how can I get the title bar's color(to make toolbars background color)? And I found something for mac to make compatible titlebar and toolbars: "setUnifiedTitleAndToolBarOnMac(true)". Is there a equivalent thing for ubuntu/unity/gtk desktops?