Iterate through the contents of l_of_l and assign the third element of sublist to a new list called third.

nestedList.py

third = []
l_of_l = [['purple', 'mauve', 'blue'], ['red', 'maroon', 'blood orange', 'crimson'], ['sea green', 'cornflower', 'lavender', 'indigo'], ['yellow', 'amarillo', 'mac n cheese', 'golden rod']]
for i in l_of_l:
    third.append(i[2])