Help complete the data link on '99 deville

After market radio has been installed. The radio works right other than a few things.

1. I have completed installing 18awg. 4 core trailer wire from under dash where the aftermarket radio is installed to the trunk where I plan to finalize the data link connections to the factory radio.

The issue I'm having now is do I need to tap into any specific wires for the hot lead and the negative ground for the factory radio?

I have the two purple data link lines spliced to 2 wires running to the trunk I just need to complete the hot and ground and unsure if I need to access the accessory hot Ignition Wire or the Battery wire?

Is there any specific/s or will any hot and negative ground do.

I am at a stand still with my car apart. My Factory Harness shows Orange and green wires but it don't jive with my printout of the so called factory wiring diagram I have.
thx..