Adding speakers to base SS

[ReversePandaLuci]

So I have a 24 pure with the base SS. I have read through much of what’s out there, albeit much less information available for the base sound system. I recently added a JL powered 10 using a very similar method to that of smistry007 and McGriddle. But since I have the base SS I have the speaker cut outs in the rear rear deck for a component speaker set so I was thinking why not put in a set of speakers. Initially I thought I could simply take the signal from rear centered mounted sub as I did for adding the subwoofer but it’s clear that signal frequency is too low. But since the amp is right there and I would assume all of the speaker wires are there I should be able to tap into a proper full signal. So that is my question, is there a wiring diagram or has anyone identified the which wires are for each signal?

I’m pretty confident that the two purple, yellow and red on the brown plug on the right provide the signal to the sub.