Wiring scheme

[Snacky]

Need to hook some aux lights and the instructions say to tap into the highbeam's positive and negative wires.

 

I looked at them but they are not marked or color coded (ie red and black) the usual way.

 

What is there, is an Orange wire and a Purple wire.  Anyone know which is positive?

 

Vehicle is a 99 gmc sierra

[mnstrmdnss]

if gm is consistant with their wiring on vehicles, the purple should be ground and the orange should be positive.