What color are the trees the leaves are on?
The trees are brown.
    src        edge_attr  dst
0     2  to the right of   15
1     2   to the left of   16
2     4   to the left of    6
3     4  to the right of   12
4     5               on    6
5     5  to the right of   12
6     5   to the left of    6
7     6  to the right of   12
8     6  to the right of    4
9     6  to the right of    5
10    7  to the right of    9
11    9   to the left of    7
12   10  to the right of   16
13   10  to the right of   11
14   11   to the left of   10
15   11  to the right of   16
16   12   to the left of    5
17   12   to the left of    6
18   12   to the left of    4
19   15   to the left of    2
20   16   to the left of   10
21   16  to the right of    2
22   16   to the left of   11