seatheating aftermarket

Good day,

I just installed some new aftermarket seat heating mats in my 9-3 convertible. As the panel doesnt have the seat heating switches I bought a new panel on ebay what does have this. Now i noticed that on the back of the panel there are only two outlets and not particular for the seat heating as far as I noticed. On the back of the dashboard theres a cable of wires. I want to put my two (red and white) wires directly on the right seat heater cable. Wich colour of cable do i have to use?
Joost