Fog lamp on 1982 US 911SC

[dean1057]

Hi,
Just having rear bumper painted and binning the US buffers, replacing with a pair of euro buffers on the above car and thought I'd do the rear fog lamp conversion on right hand rear reverse light using a red brake bulb.
Found the loom that hangs at the back of the left hand rear lights, in there is two orange wires, both look identical, even looked way back under the sheath.
Has anybody done this conversion? I'm told using a Pelican forum that the wire under the fog light switch will be white and green that you use to connect to the fog light switch. Just puzzled why I have two identical wires. The light unit itself is already earthed at the back with a brown wire.

Pelican forum tells me the two wires should be different and use the one with the yellow and red markers on it.
Can anybody advise please.