Ohh… now I see. Yep, that is correct. Each color is differently keyed.
There are a couple of teams that I’ve seen use the green ones and take a dremel to them to mate them with the red. They will use green on their battery chargers and red on the batteries to make it more difficult to plug the wrong things together.
We use a different approach. We bolt down any SB50 that isn’t on a battery. Always plug a loose connector into a bolted down connector.