I have a SM8 and took apart the 8 pin mic connector to let you know which colors are wired where:
Pin 1 = White
Pin 2 = Black
Pin 3 = Bue
Pin 4 = No Connection
Pin 5 = Red
Pin 6 = Brown
Pin 7 = Shield
Pin 8 = No Connection
I hope this answers your questions. By the way I believe ICOM sells the cable that comes out of the SM8. It has a connector on both sides with a ferite bead on one end.
Julius Jones (w2IHY)