def increment_unnamed_colormap(name, names):
    """Increment name for unnamed colormap.

    Parameters
    ----------
    name : str
        Name of colormap to be incremented.
    names : str
        Names of existing colormaps.

    Returns
    -------
    name : str
        Name of colormap after incrementing.
    """
    if name == '[unnamed colormap]':
        past_names = [n for n in names if n.startswith('[unnamed colormap')]
        name = f'[unnamed colormap {len(past_names)}]'
    return name