def is_column_fully_sorted(column, max_column_length):
    """Check if a column is fully sorted, that is, if it's empty or full of the same colour

    >>> is_column_fully_sorted(['b', 'b', 'b', 'b'], 4)
    True
    >>> is_column_fully_sorted([], 4)
    True
    >>> is_column_fully_sorted(['b', 'b', 'b', 'o'], 4)
    False
    >>> is_column_fully_sorted(['b', 'b', 'b'], 4)
    False

    :param column: list to check sorted status
    :param max_column_length: length of a full column
    :returns: whether the column is fully sorted
    """
    return len(column) == 0 or column.count(column[0]) == max_column_length