Austria and Germany didn't change from red ground to yellow/green until at least 1967, Austria maybe even later. I think yellow/green was chosen because it has never been used for anything else before. The only other striped conductor I've ever heard of is the old Swiss red/yellow ground, which changed to yellow/green pretty early (I think 1950ies or early 60ies).
Until today black/grey/red cables are found not that seldom here, but we don't even learn the old colors at school any more. At least tow class mates asked me whether I had any idea what the red and grey wires at home could be...
