What color are the letters?
The letters are black.
    src        edge_attr  dst
0     1  to the right of    7
1     1  to the right of    3
2     1  to the right of    9
3     1  to the right of   14
4     2  to the right of   15
5     3   to the left of    1
6     3  to the right of    7
7     3   to the left of   14
8     4  to the right of   10
9     4   to the left of   11
10    7   to the left of    3
11    7   to the left of    1
12    7   to the left of   14
13    7   to the left of    9
14    8  to the right of   15
15    9   to the left of   14
16    9   to the left of    1
17    9  to the right of    7
18   10   to the left of    4
19   10   to the left of   11
20   11  to the right of    4
21   11  to the right of   10
22   13  to the right of   15
23   14  to the right of    3
24   14   to the left of    1
25   14  to the right of    9
26   14  to the right of    7
27   15   to the left of    2
28   15   to the left of    8
29   15   to the left of   13