How to change the background color in PyQt4

I am really new to PyQt4(just learned what it is two days ago) and I know that this question probably has a really easy answer but I can't find it anywhere. I am trying to change the background color of the window to black. I have this code so far.

import sys
from PyQt4 import QtGui

class Display(QtGui.QMainWindow):
    def __init__(self):
        super(Display, self).__init__()
        self.ShowFullScreen()
        self.show()

if name == '__main__':
    app = QtGui.QApplication(sys.argv)
    GUI = Display()
    sys.exit(app.exec())

When I run this I get a white window. Is there a method I could run to change it to black?