Final answer:
The wire color code for the stop signal in a 7-way trailer connector is typically red, used for stop lights and brake signals.
Step-by-step explanation:
The wire color code for the stop signal circuit on a trailer with a 7-way power connector is typically the red wire. In the standard wiring configuration for a 7-way connector, the red wire is assigned to the stop lights and/or brake signals of the trailer.
It is important to note that while this color coding is widely accepted, it's always best to consult the trailer's wiring diagram or manufacturer's specifications to confirm, as there can sometimes be variations.