W221 S550 illuminated door sill installation

I purchased a set of illuminated door sills for my 2007 S550 (W221) from formymercedes (@ $220). The installation process has been pretty straight forward even without detailed instructions, but I have a question.

I pulled the B-pillar panel in an attempt to find a hot lead and ground that turn on/off with the door. There is a courtesy light in the bottom of the door and I pulled the light hoping it would identify the wire colors that I needed to tap in the pillar, but somewhere in the door panel it was converted to a ribbon cable.

Can anyone tell me the correct wire colors for +/- in the B-pillar that will allow the lights to turn on and off with the courtesy light for the drivers and passenger side?

Thanks!