According to the NEC, it is perfectly acceptable to use whatever color you have on the truck for an ungrounded conductor, as long as it is not white, gray, or green. There is an additional restriction on orange, which must be and may only be used on the 208V-to-ground leg of a four-wire delta, if such a system exists on the premises.
Many jurisdictions, including my own, are more restrictive.
Yes, there is double-lugging going on in here. That might have been legal at the time.
For the ungrounded branch circuit conductors, I see three colors: yellow, orange, purple, and another color which is debatable. Is it blue? Gray? Green? My wife voted for teal. It looked green enough to me that I wouldn't have used it for a phase.
The question is, if it is green: Is this grandfathered?
