Actually, the dark green version is the 23761.
The 761 came in the normal light green associated with most semaphores. The dark green is a variation, usually in poor condition due to paint chipping as the chips are more visible on the darker paint. The 23761 is always in the lighter green. All boxed versions I have seen in 40 yrs are the lighter green. The black wire is the ground or base. It simply connects to the lug which is screwed directly into the base.
Rich
