wxpython change background color

1import wx
2
3class my_window(wx.Frame):
4    def __init__(self, parent, id):
5        wx.Frame.__init__(self,parent,id,'My Window', size=(300,200))
6
7        #Panel for frame
8        self.panel = wx.Panel(self)
9        self.SetBackgroundColour('blue')
10
11if __name__ == "__main__":
12    app=wx.PySimpleApp()
13    frame=my_window(parent=None,id=-1)
14    frame.Show()
15    app.MainLoop()