FWIW, our mid 2016 manufactured car (Sport) came with the blue highlights and badges. Pretty sure it was just an oddity - someone in marketing decided blue was the colour of EV so slapped it on for a bit, then they realised it costs, so took it off again? Maybe folk objected to the hybrid badge??
I'd be amazed if you find a dealer that even knows about it, let alone one that can give you an honest and accurate answer!
Do bear in mind that a 16/66 plate may well have sat unsold for a while. Mine was manufactured in July and sold in December. There were a few detail changes that came in early 2016, like the revised charging socket (the one that doesn't let water make its way into the charger electronics box!) so it could be just timing.
Curious to hear what the dealer says anyway so please keep us posted, and of course, pictures of the car when you get it or it never happened