def get_turn_on_descriptions(get_turn_on, initial_state, current_state):
    """
    Get all 'turn on' descriptions from the current state (if any).
    Parameters
    ----------
    get_turn_on: function
        Function that gets the color of light which is on.
    initial_state: nd.array
        Initial state of the environment.
    current_state: nd.array
        Current state of the environment.

    Returns
    -------
    descr: list of str
        List of 'turn on' descriptions satisfied by the current state.
    """
    turn_on_descriptions = []
    light_on = get_turn_on(initial_state, current_state)
    for c in light_on:
        turn_on_descriptions.append('Turn on the {} light'.format(c))
    return turn_on_descriptions.copy()