def set_left_colon(self, show_colon):
        """Turn the left colon on with show color True, or off with show colon
        False.  Only the large 1.2" 7-segment display has a left colon.
        """
        if show_colon:
            self.buffer[4] |= 0x04
            self.buffer[4] |= 0x08
        else:
            self.buffer[4] &= (~0x04) & 0xFF
            self.buffer[4] &= (~0x08) & 0xFF
Turn the left colon on with show color True, or off with show colon
        False.  Only the large 1.2" 7-segment display has a left colon.