def filter_colony_properties(colony_df, cluster_params, colony_props):
    """Assign -1 label to clusters not meeting these criteria."""
    if not cluster_params['min_density'] < colony_props['density'
        ] < cluster_params['max_density']:
        colony_df['Colony'] = -1
    if not cluster_params['min_roundness'] < colony_props['roundness'
        ] < cluster_params['max_roundness']:
        colony_df['Colony'] = -1
    return colony_df
