I've also checked on my ignition switch, and I only have the 4 wire colors indicated. There are (5) terminals on the switch, and it is the inner one in the row of (4) terminals, that is next to the notch on the edge of the switch body which is left open/unconnected to any wire. The green wire w/black stripe is left hanging, and if memory serves, I think that is a switched +12V wire, to be used for connecting to voltmeters, etc.
Ken also has a 'mystery wire' that not sure were it goes - or whether it is part of the factory wiring or not.