Is the color of the letters different than the color of the walls?
Yes, the walls are blue and the letters are white.
    src        edge_attr  dst
0     1  to the right of   11
1     1  to the right of   12
2     2  to the right of   11
3     3  to the right of   11
4     4  to the right of   12
5     4  to the right of   11
6     4  to the right of   10
7     5  to the right of   11
8     6  to the right of   11
9     6  to the right of   10
10    6  to the right of   12
11    9               on    8
12    9  to the right of   11
13    9  to the right of   12
14    9  to the right of   10
15   10   to the left of    4
16   10   to the left of    9
17   10               by   11
18   10   to the left of    6
19   11   to the left of    2
20   11   to the left of    1
21   11   to the left of    9
22   11   to the left of    3
23   11   to the left of    4
24   11   to the left of    5
25   11   to the left of    6
26   12   to the left of    1
27   12   to the left of    4
28   12   to the left of    9
29   12   to the left of    6