In Australia they used a different colour for the wire from the switch to
the lamp. (if the switch branches from the lamp.
"fusebox" ================= lamp fixture ================= switch
red+black+ground red+white
They also do red+white+blue to switch two devices (eg lamp and fan)
Misusing the neutral (or ground) colour is a big no-no
The current AS/NZS 3000 Wiring Rules allow sleeving of a conductor at
the terminations to indicate a live conductor. So for example, a twin
of red/black may be sleeved at each end to indicate two live
conductors and run to the switch. In Aus there is a prohibition on
sleeving a green, grn/yl or yellow conductor. In NZ the prohibition is
on green or grn/yl only.
In NZ at least it used to be acceptable to sleeve both the black &
green conductors of a three core cable to use for a two way light
switch for example. This is no longer allowed because the green can't
be sleeved & a different cable must be used e.g. red/white/blue, with
the blue sleeved.
