Is the tail thick and green?
No, the tail is thick but black.
    src        edge_attr  dst
0     1   to the left of    2
1     2  to the right of   10
2     2  to the right of    1
3     2  to the right of    5
4     2           behind   13
5     4  to the right of    8
6     5               on   13
7     5   to the left of    2
8     6  to the right of   12
9     7  to the right of   12
10    8   to the left of    4
11   10   to the left of    2
12   12   to the left of    6
13   12   to the left of    7
14   13      in front of    2