# -*- coding: utf-8 -*-
 
# Form implementation generated from reading ui file 'TabWidget.ui'
#
# Created by: PyQt5 UI code generator 5.12.1
#
# WARNING! All changes made in this file will be lost!
 
from PyQt5 import QtCore, QtGui, QtWidgets
 
 
class Ui_MainWindow(object):
  def setupUi(self, MainWindow):
    MainWindow.setObjectName("MainWindow")
    MainWindow.resize(800, 600)
    self.centralwidget = QtWidgets.QWidget(MainWindow)
    self.centralwidget.setObjectName("centralwidget")
    self.tabWidget = QtWidgets.QTabWidget(self.centralwidget)
    self.tabWidget.setGeometry(QtCore.QRect(110, 60, 521, 411))
    self.tabWidget.setObjectName("tabWidget")
    self.tab = QtWidgets.QWidget()
    self.tab.setObjectName("tab")
    self.tabWidget.addTab(self.tab, "")
    self.tab_2 = QtWidgets.QWidget()
    self.tab_2.setObjectName("tab_2")
    self.tabWidget.addTab(self.tab_2, "")
    MainWindow.setCentralWidget(self.centralwidget)
    self.menubar = QtWidgets.QMenuBar(MainWindow)
    self.menubar.setGeometry(QtCore.QRect(0, 0, 800, 26))
    self.menubar.setObjectName("menubar")
    MainWindow.setMenuBar(self.menubar)
    self.statusbar = QtWidgets.QStatusBar(MainWindow)
    self.statusbar.setObjectName("statusbar")
    MainWindow.setStatusBar(self.statusbar)
 
    self.retranslateUi(MainWindow)
    self.tabWidget.setCurrentIndex(0)
    QtCore.QMetaObject.connectSlotsByName(MainWindow)
 
  def retranslateUi(self, MainWindow):
    _translate = QtCore.QCoreApplication.translate
    MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
    self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab), _translate("MainWindow", "Tab 1"))
    self.tabWidget.setTabText(self.tabWidget.indexOf(self.tab_2), _translate("MainWindow", "Tab 2"))

# -*- coding: utf-8 -*-
 
import sys
from PyQt5.QtWidgets import QApplication, QMainWindow
from TabWidget import Ui_MainWindow
 
 
class ChangeTabColor(Ui_MainWindow, QMainWindow):
 
  def __init__(self):
    super(ChangeTabColor, self).__init__()
    self.setupUi(self)
    self.setFixedSize(self.width(), self.height())
    self.tabWidget.setTabsClosable(True)
    str = "QTabBar::tab{background-color:rbg(255,255,255,0);}"
    self.tabWidget.setStyleSheet(str)
 
 
def ui_main():
  app = QApplication(sys.argv)
  w = ChangeTabColor()
  w.show()
  sys.exit(app.exec_())
 
 
if __name__ == '__main__':
  ui_main()

str = "QTabBar::tab{background-color:rbg(255,255,255,0);}"
self.tabWidget.setStyleSheet(str)

str = "QTabBar::tab{background-color:rbg(255,255,255,0);}" +    "QTabBar::tab:selected{color:red;background-color:rbg(255,200,255);} "

  def __init__(self):
    super(ChangeTabColor, self).__init__()
    self.setupUi(self)
    self.setFixedSize(self.width(), self.height())
    self.tabWidget.setTabsClosable(True)
    str = "QTabBar::tab{background-color:rbg(255,255,255,0);}" +        "QTabBar::tab:selected{color:red;background-color:rbg(255,200,255);} "
    self.tabWidget.setStyleSheet(str)
    self.tabWidget.currentChanged.connect(self.slot_small_tab)
 
  def slot_small_tab(self):
    if self.tabWidget.currentIndex() == 0:
      print('666')
    elif self.tabWidget.currentIndex() == 1:
      print('222')
    else:
      pass