Does the large train have gray color?
Yes, the train is gray.
    src        edge_attr  dst
0     0   to the left of   13
1     0   to the left of   12
2     1  to the right of    3
3     2               of    7
4     3   to the left of    8
5     3   to the left of    1
6     4  to the right of    5
7     5   to the left of    4
8     5   to the left of    7
9     6   to the left of    9
10    6  to the right of   13
11    6  to the right of   10
12    6  to the right of   12
13    7  to the right of    5
14    8  to the right of    3
15    9  to the right of    6
16    9               on    1
17   10   to the left of    6
18   12   to the left of    6
19   12  to the right of    0
20   13   to the left of    6
21   13  to the right of    0