ECS offers 10 different colored coding keys, which can be inserted into the multifunction area of the connector to prevent damaging the system due to incorrect insertion of cards with
different logic. The coding keys are inserted into the connector after the connector has been installed into the board through the use of a special insertion tool. For 5.0 V logic, CompactPCI
uses brilliant blue, and for 3.3 V logic, cadmium yellow is used.