Stereo on old radios harness

So I’m almost done installing the stereo in my dart. I heard from a friends experience that I should just run a wire straight from the battery but I also have a 60amp alternator. There are 4 wires that come off the old radio. A black and a green one for the 5 by 9 speaker that’s in the dash.(at least I think it’s a 5 x 9). Then a red one and and orange wire which I assume are for power and ground. They are on a connector(see below). My question is which one is for the power because there is a yellow wire from the new stereo and I am not sure which to crimp it too.

Red is 12v pos, radio case is ground, orange is for the dial light. Speaker is usually 4 x 10.

X2. Ground is through the case, org is dimmer controlled panel lighting, red is switched accessory

You dont need to run another wire for just a head unit. The original wire will work just fine.