def latexify(labels, default_latex_labels=None):
    """
    Return a LaTeX-ified label.

    Args:
        labels (str or list-type of str objects): The label(s) to latexify. 
        default_latex_labels (dict): Dictionary of common labels to use.

    Returns:
        LaTeX-ified label.
    """

    common_labels = {
        "teff": "$T_{\\rm eff}$ (K)",
        "feh": "[Fe/H]",
        "logg": "$\log{g}$",
        "alpha": "[$\\alpha$/Fe]",
        "xi": "$\\xi$ (km s$^{-1}$)"
    }

    if default_latex_labels is not None:
        common_labels.update(default_latex_labels)
    
    listify = True
    if isinstance(labels, str):
        listify = False
        labels = [labels]

    latex_labels = []
    for label in labels:

        if label.startswith("doppler_sigma_"):
            color = ["blue", "green", "red", "ir"][int(label.split("_")[-1])]
            latex_labels.append("$\sigma_{\\rm doppler," + color + "}$ ($\\AA{}$)")

        else:
            latex_labels.append(common_labels.get(label, label))

    if not listify:
        return latex_labels[0]

    return latex_labels