Do the wheels have silver color?
No, the wheels are black.
   src        edge_attr  dst
0    4  to the right of   10
1    4  to the right of   11
2    5  to the right of   10
3    5  to the right of   11
4   10   to the left of    4
5   10   to the left of    5
6   11   to the left of    5
7   11   to the left of    4