What color is the vehicle behind her?
The vehicle is gray.
   src        edge_attr  dst
0    0           behind    1
1    1           behind    2
2    1             near    2
3    1          wearing    7
4    1      in front of    0
5    1          next to    2
6    2   to the left of    4
7    2             near    1
8    2      in front of    1
9    4  to the right of    2