def covar_plotter3d_plotly(embedding, rieman_metric, inspect_points_idx,
                           colors, **kwargs):
    """3 Dimensional Covariance plotter using matplotlib backend."""
    def rgb2hex(rgb):
        return '#%02x%02x%02x' % tuple(rgb)
    return [ plt_data for idx in inspect_points_idx
             for plt_data in plot_ellipse_plotly(
                rieman_metric[idx], embedding[idx],
                color=rgb2hex(colors[idx]), **kwargs) ]
3 Dimensional Covariance plotter using matplotlib backend.