src/vs/workbench/browser/parts/views/viewPane.ts/ViewPane/getBackgroundColor
class ViewPane:	protected getBackgroundColor(): string {
		switch (this.viewDescriptorService.getViewLocationById(this.id)) {
			case ViewContainerLocation.Panel:
				return PANEL_BACKGROUND;
			case ViewContainerLocation.Sidebar:
			case ViewContainerLocation.AuxiliaryBar:
				return SIDE_BAR_BACKGROUND;
		}

		return SIDE_BAR_BACKGROUND;
	}