Question Brake light wiring

[DonC]

I’m trying to install a ST2 brake light module. (It flashes the brake light if you slow by engine braking or downshift and don’t use the brakes). The instructions say to tap into the grey/red, grey/black, and brown wires. My rear lights have blue, brown, yellow, grey wires. (Grey and brown goes to the license plate light). Anyone know what color the power and signal wires are? (Brown is ground?)
Any info is appreciated.

 

[Star-Lord]

I have found in several cases, that the Brown solid colored wires are Ground..

Brown = Ground