import sys
from PyQt5.QtWidgets import (QWidget, QPushButton, QFrame,
                             QColorDialog, QApplication)
from PyQt5.QtGui import QColor


class Example(QWidget):

    def __init__(self):
        super().__init__()

        self.initUI()

    def initUI(self):
        col = QColor(0, 0, 0)

        self.btn = QPushButton('选择你喜欢的颜色', self)
        self.btn.move(20, 20)

        self.btn.clicked.connect(self.showcolor)

        self.frm = QFrame(self)
        self.frm.setStyleSheet("QWidget { background-color: %s }"
                               % col.name())
        self.frm.setGeometry(130, 22, 100, 100)

        self.setGeometry(300, 300, 250, 180)
        self.setWindowTitle('请选择你喜欢的颜色')
        self.show()

    def showcolor(self):
        col = QColorDialog.getColor()

        if col.isValid():
            self.frm.setStyleSheet("QWidget { background-color: %s }"
                                   % col.name())


if __name__ == '__main__':
    app = QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


pyqt颜色_系统