Change the color of the main interface with the python library PyQt5

Question

The code below changes the color of the interface if it is Qwidget type. Can I change the interface color if it is Qmainwidow? Thanks for the help

import sys
from PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout)

# class Wind(QMainWindow):  # this what i need
class Wind(QWidget):   
    def __init__(self):      #__init__ method
        super(Wind, self).__init__()
        self.scaleFactor = 0.0

        self.widget = QWidget(self)
        layout = QVBoxLayout(self)
        layout.addWidget(self.widget)

        self.widget.setStyleSheet("""
                .QWidget {
                    background-color: rgb(0, 200, 0);
                    }
                """)

        self.setWindowTitle("first-window")
        self.resize(500, 400)


if __name__ == '__main__':

    app = QApplication(sys.argv)
    imageViewer = Wind()
    imageViewer.show()
    sys.exit(app.exec_())

Answer 1

This seems to be the code properly dispalyed.

from PyQt5.QtWidgets import (QApplication, QMainWindow, QWidget, QVBoxLayout) 
import sys

#class Wind(QWidget): #Class Name

class Wind(QMainWindow): # Class Name
    def __init__(self):      #__init__ method
        super(Wind, self).__init__()
        self.scaleFactor = 0.0

        self.widget = QWidget(self)
        layout = QVBoxLayout(self)
        layout.addWidget(self.widget)

        self.widget.setStyleSheet("""
                .QWidget {
                    background-color: rgb(0, 200, 0);
                    }
                """)

        self.setWindowTitle("first-window")
        self.resize(500, 400)
if __name__ == '__main__':
    app = QApplication(sys.argv)
    imageViewer = Wind()
    imageViewer.show()
    sys.exit(app.exec_())