In article ,
G&M wrote:
White is often used for both 110v wires in sound and lighting touring
equipment to identify it as NOT one fo the three 240v phases or directly
connected to it.

That certainly makes more sense than yellow, but of course might be much
more difficult to obtain.

Up to the 1970s white (line-ish) and black (neutral-ish)
were used.

If it's off an isolating transformer, there's no such thing.

--
*Acupuncture is a jab well done.*

Dave Plowman London SW
To e-mail, change noise into sound.