[README CORRECTION] Todo 4 coloring example

[linj45]

why nanan is [‘yellow’, ‘grey’, ‘green’, ‘grey’, ‘yellow’] when solution is FUNNY.

In my understanding, we remove one 'n' when we find the green spot, then we remove one 'n' for the first yellow spot, i don't get why the last character is also yellow

[chinyi0523]

You're right, it should be
[‘yellow’, ‘grey’, ‘green’, ‘grey’, ‘grey’]
Please also pay attentions to TAs' update, thanks