What color are the square tiles?
The tiles are black.
    src        edge_attr  dst
0     0  to the right of    4
1     0  to the right of    5
2     2   to the left of   10
3     3  to the right of    7
4     4   to the left of    0
5     5   to the left of    0
6     6   to the left of   11
7     7   to the left of    3
8     7   to the left of   10
9    10  to the right of    2
10   10  to the right of    7
11   11  to the right of    6