Wiring color code polarity

[2Big2Bite]

On the door of my almera N16 04 im trying to find negative and positive on the wires and i dont have a meter.

But the colors are:
LF: Green, and green with white line
RF: brown, and brown with white line

What is negative and what is positive on those speaker wires?

Thanks

 

[edk]

@Liam might have that knowledge.

 

[Liam]

I always use white lined as the negative. Could be wrong though.