Here is a code snippet to add look and feel using java's UIManager in jython. Add this snippet to your code and then reference it in your class __init__ function. Example from javax.swing import UIManager class App: def __init__(self): setTheme("Nimbus") #If none specified it uses default LAF #...Rest of code #ADD THIS FUNCTION def setTheme(theme=None): lookAndFeel = None for info in UIManager.getInstalledLookAndFeels(): if info.getName() == theme: lookAndFeel = info.getClassName()