Make a palette that blends from a deep gray to `color`.

    Parameters
    ----------
    color : matplotlib color
        hex, rgb-tuple, or html color name
    n_colors : int, optional
        number of colors in the palette
    reverse : bool, optional
        if True, reverse the direction of the blend
    as_cmap : bool, optional
        if True, return as a matplotlib colormap instead of list

    Returns
    -------
    palette : list or colormap

def dark_palette(color, n_colors=6, reverse=False, as_cmap=False):
    """Make a palette that blends from a deep gray to `color`.

    Parameters
    ----------
    color : matplotlib color
        hex, rgb-tuple, or html color name
    n_colors : int, optional
        number of colors in the palette
    reverse : bool, optional
        if True, reverse the direction of the blend
    as_cmap : bool, optional
        if True, return as a matplotlib colormap instead of list

    Returns
    -------
    palette : list or colormap

    """
    gray = "#222222"
    colors = [color, gray] if reverse else [gray, color]
    return blend_palette(colors, n_colors, as_cmap)