PyQt5 - Changing font color under cursor

Question

I'm trying to change the color (Red) of the font that will be highlighted. The problem I'm facing is, as soon as I highlight the first word, all the following text becomes Red.

def cursorPosition(self):
    logging.debug("Cursor Positiong changed")
    self.cursor = self.ui.captureWindow.textCursor()

    if self.cursor.hasSelection():
        fmt = QTextCharFormat()
        fmt.setForeground(Qt.red)

        logging.debug(self.cursor.selectedText())

        # We insert the new text, which will override the selected text
        self.cursor.insertText(self.cursor.selectedText(), fmt)
        # txt = '<p style="color:red;">' + self.cursor.selectedText() + '</p> '
        # self.cursor.insertHtml(txt)

        # And set the new cursor
        self.ui.captureWindow.setTextCursor(self.cursor)

I've tried doing it with two methods, insertText and insertHtml. insertHtml works if there is a space after the closing tag. Remove that space, it behaves the same way as insertText, everything will be red after the first highlight.