Is there any helmet that is not silver?
Yes, there is a black helmet.
    src        edge_attr  dst
0     0             near    8
1     0               on    7
2     0   to the left of    1
3     1             near    8
4     1  to the right of    0
5     1               on    7
6     2               of    9
7     5   to the left of   11
8     7               by    4
9     7               by    8
10    8             near    0
11    8             near    1
12    9            below   13
13    9               on   14
14   10   to the left of   12
15   11  to the right of    5
16   12  to the right of   16
17   12  to the right of   10
18   13          wearing    6
19   13           riding    9
20   13             with    3
21   13          wearing    3
22   13            above    9
23   13          wearing   12
24   15  to the right of   16
25   15               of    9
26   16   to the left of   12
27   16   to the left of   15
28   16               of    9