simplify setting the border color of clients

client.h

@@ -323,6 +323,14 @@ client_send_close(Client *c)
 	wlr_xdg_toplevel_send_close(c->surface.xdg->toplevel);
 }
 
+static inline void
+client_set_border_color(Client *c, const float color[static 4])
+{
+	int i;
+	for (i = 0; i < 4; i++)
+		wlr_scene_rect_set_color(c->border[i], color);
+}
+
 static inline void
 client_set_fullscreen(Client *c, int fullscreen)
 {