def postprocess(self, value: str | None) -> str | None:
        """
        Parameters:
            value: Expects a hex `str` returned from function and sets color picker value to it.
        Returns:
            A `str` value that is set as the color picker value.
        """
        if value is None:
            return None
        else:
            return str(value)

        Parameters:
            value: Expects a hex `str` returned from function and sets color picker value to it.
        Returns:
            A `str` value that is set as the color picker value.
        
gradio/components/color_picker.py