What's that line again? "The nice thing about standards is that there are so many to chose from."
![[Linked Image]](https://www.electrical-contractor.net/ubb/biggrin.gif)
The problem with trying to introduce any one standard now is that a lot of people won't want to change something which they perceive as having worked perfectly well within their own industry for a long time.
When faced with something such as red and green having opposite meanings in different plants, whoever changed is going to have a real tough time making sure there are no mishaps too.
There's an interesting post in one of the threads BJ linked to about the Navy not using red indicators at all, due to the use of red background lighting for "silent running."