The knee pads to the left of the other knee pads have what color?
The knee pads are gray.
    src        edge_attr  dst
0     2   to the left of    7
1     3          wearing    9
2     3               in    1
3     3   to the left of    6
4     4  to the right of    8
5     5   to the left of    6
6     6  to the right of    3
7     6  to the right of    9
8     6  to the right of    5
9     7  to the right of   15
10    7  to the right of    2
11    8   to the left of    4
12    8   to the left of   14
13    9   to the left of    6
14   10  to the right of   11
15   11   to the left of   10
16   12               on   13
17   14  to the right of    8
18   15   to the left of    7