I got used to seeing lots of colors around commercial shops where they had wire carts with lots of spools with every color they make. The good ones had a color code on the side of the cart of what the standard was in that installation. Most of the time they followed the standard. The only danger in that is when someone doesn't and you get used to it being "standard". I have seen guys get into 277 when it was supposed to be violet/grey and ended up black/white. 120v stuff expells the magic smoke pretty fast.
