2000 V40 MAP Sensor Ground Wire Color Question

[clickraider]

I have replaced the sensor 4 times and the check engine light with a low circuit error keep coming out. today I replaced it again and a small section of the harness too. I noticed the wires are in very poor condition on the inside after splicing them. My question here is the function of each color wire. I really just need the color of the ground wire.

Thanks in advance!