dieselpb

I'm figuring out how to remove my Nak head unit and replace it with an aftermarket one I already have. I understand that I have to make my own harness from this guide https://www.clublexus.com/forums/ls-...b-working.html but I'm having a bit of trouble understanding. I don't feel like ripping the stereo out of my car right now, so hopefully someone can give me some clarification. Using this pic for example.
Since the grey plug is the C plug, would the B plug be the white plug or the blue plug?