When I call this code
fill_main_lcd = lv_scr_act();
line1 = lv_line_create(lv_scr_act(), NULL);
lv_obj_set_style_local_bg_color(fill_main_lcd, LV_OBJ_PART_MAIN, 0, LV_COLOR_BLUE);
Does it mean that the screen should immediately fill with the specified color?