The confusion starts with the fact that it is both grounded and grounding.
On smaller services it is not unusual to have a non fused disconnect (480V) [for the utility] ahead of a standard meter socket and then the Service disconnect. The grounded leg IS BONDED to all enclosers ahead of the service disconnect as required by the NESC. It is then bonded at the service disconnect, per the NEC.
The service disconnect could be two pole even though it is a three phase system.
Connections to the ground rod etc. is done ONLY from the service disconnect. No additional bond wire is required between the utility disconnect, the meter socket and the service disconnect because the grounded leg is doing all those bonds.
If that wire is insulated what color should it be ?
