I have search far and wide on how you can paint the background color of a button or GenButton with a pattern such as lines or cross hatch. I have seen examples of wx DirectContext so that you can draw objects with patterns instead of just solid colors but it seems that this is only for specific shapes and not the color of button objects. Does the dc or gc library allow to paint on these objects. I know that I have to create an event handler for OnPaint and OnResize but I may be missing some steps so that it applies this to the button itself.
The wxPython package uses native widgets in its core widgets as much as possible. Thus, the wx.Button widget is going to be a native widget that you can only modify via the methods mentioned in the documentation. As Igor mentioned, you can try using SetBackgroundColour() or SetForegroundColour(), although depending on your platform's button widget, they may or may not work.
What you really want is a custom widget. I recommend checking out the GenericButtons, PlateButton and GradientButton for examples. You might even be able to use a GenericButton directly and paint its background as you mentioned.
WxPython: Setting the background of buttons with wx.Brush