restore and respect rootcolor

config.def.h

@@ -7,6 +7,7 @@
 static const int sloppyfocus               = 1;  /* focus follows mouse */
 static const int bypass_surface_visibility = 0;  /* 1 means idle inhibitors will disable idle tracking even if it's surface isn't visible  */
 static const unsigned int borderpx         = 1;  /* border pixel of windows */
+static const float rootcolor[]             = COLOR(0x222222ff);
 static const float bordercolor[]           = COLOR(0x444444ff);
 static const float focuscolor[]            = COLOR(0x005577ff);
 static const float urgentcolor[]           = COLOR(0xff0000ff);

dwl.c

@@ -361,6 +361,7 @@ static struct wlr_cursor_shape_manager_v1 *cursor_shape_mgr;
 static struct wlr_cursor *cursor;
 static struct wlr_xcursor_manager *cursor_mgr;
 
+static struct wlr_scene_rect *root_bg;
 static struct wlr_session_lock_manager_v1 *session_lock_mgr;
 static struct wlr_scene_rect *locked_bg;
 static struct wlr_session_lock_v1 *cur_lock;
@@ -2181,6 +2182,7 @@ setup(void)
 
 	/* Initialize the scene graph used to lay out windows */
 	scene = wlr_scene_create();
+	root_bg = wlr_scene_rect_create(&scene->tree, 0, 0, rootcolor);
 	for (i = 0; i < NUM_LAYERS; i++)
 		layers[i] = wlr_scene_tree_create(&scene->tree);
 	drag_icon = wlr_scene_tree_create(&scene->tree);
@@ -2564,6 +2566,9 @@ updatemons(struct wl_listener *listener, void *data)
 	/* Now that we update the output layout we can get its box */
 	wlr_output_layout_get_box(output_layout, NULL, &sgeom);
 
+	wlr_scene_node_set_position(&root_bg->node, sgeom.x, sgeom.y);
+	wlr_scene_rect_set_size(root_bg, sgeom.width, sgeom.height);
+
 	/* Make sure the clients are hidden when dwl is locked */
 	wlr_scene_node_set_position(&locked_bg->node, sgeom.x, sgeom.y);
 	wlr_scene_rect_set_size(locked_bg, sgeom.width, sgeom.height);