def _l2rgb(self, mode):
        """Convert from L (black and white) to RGB.
        """
        self._check_modes(("L", "LA"))

        bands = ["L"] * 3
        if mode[-1] == "A":
            bands.append("A")
        data = self.data.sel(bands=bands)
        data["bands"] = list(mode)
        return data