speed sensor wire color code

[nandy]

:cry:
I just got a state of the art gps system for my '87 325i. I installed the system and lack just the speed signal wire to complete my installation. The manual I have for my ride is not specific as to the instrument cluster location for this wire. I figured this wire ends up at the speedo but need the color code to save some time and aggravation.
any offered help will be greatly appreciated.