The first one I saw confused me for a minute but I did know there was such a thing as corner delta so I did figure it out. (and pretty proud of myself that I did it before I said something dumb) The colors they used were red, blue and white. Very patriotic and also a fairly good indicator for a 240v 3p corner system, The fact that one wasn't black was a tip off that it wasn't standard 120/240 and 2 transformers on the pole was another cue that you had 3p.
Fortunately there was a wiring diagram in the starter that confirmed this was really 3 phase but it did not say anything about the grounding.
I think if I was doing 480 corner I would use brown/yellow/gray, just because gray is the common grounded conductor color on 480 and orange can cause confusion. BOY is a common convention on 480 wye but when delta is involved it is supposed to be the high leg if this was center tapped. Omitting it alerts you something else is going on. Actually I have heard a lot of people who want BOY to go away because of the high leg thing. I think it is so ingrained in the culture that it is probably here to stay.
