extends Panel var style = StyleBoxFlat.new() func _ready(): # The Panel doc tells you which style names there are add_style_override("panel", style) set_process(true) func _process(delta): # Some basic code animation var color = Color(0.5*sin(OS.get_ticks_msec()/100.0)+0.5, 0, 0) style.set_bg_color(color) # Don't forget to update so the control will redraw update()