There are many ways to highlight the items in a listWidget. You can set the background color, foreground color or completely change the font of the items to be highlighted.
Set the foreground:
for item in listWidget.selectedItems():
item.setForeground(QBrush(Qt.green, Qt.SolidPattern))
Set the background:
for item in listWidget.selectedItems():
item.setBackground(QBrush(Qt.yellow, Qt.SolidPattern))
Or change the font of the items:
font = QFont('', -1, QFont.Bold, True)
for item in listWidget.selectedItems():
item.setFont(font)
Empty string to QFont means default font family, -1 means default font size, finally made the font bold and made it italic by setting the last parameter to True. If you don't want bold font, pass -1 instead of QFont.Bold