QPalette set QMenubar background is not working

[jiajintao]

see:

app = QApplication(sys.argv)

window = QWidget()

menubar = QMenuBar(window)

menubar.setAutoFillBackground(True)

palette = menubar.palette()
palette.setColor(palette.ColorRole.Button, Qt.GlobalColor.blue) # this line
palette.setColor(palette.ColorRole.Window, Qt.GlobalColor.red) # this line
palette.setColor(palette.ColorRole.ButtonText, Qt.GlobalColor.green)

menubar.setPalette(palette)

menu = QMenu('File')
menubar.addMenu(menu)

window.show()

if __name__ == '__main__':
    sys.exit(app.exec())

result:

this result background is no change
i'm beginner,
this why is this result, can't use qpalette on the menubar, use it on the qwidget is good, on the qtoolbar is good, why.
i don't want use to stylesheet.
help me please, thanks!

[SGaist]

Hi and welcome to devnet,

The style used to draw your application may ignore the palette changes you did. See here.

[jiajintao]

This post is deleted!

[jiajintao]

@SGaist thank your message, i solved it.