I did ask them and they won't take anymore off. They are willing to ship me out a 2016 model, but they don't offer blue any longer.
Match point. Time to make a decision.
I make it a point to return anything that's not exactly what I ordered unless it's something I unexpectedly liked a lot better - or they contacted me first.
In your case, if you don't like the new colors they offer for a 2016, I'd just ask for a full credit - including shipping both ways since it was their error and not yours - and if they balked, I'd go through my card company to get it taken care of if it's that important to you. You'll burn your bridges with the seller probably, but that's the way it goes if you get super heavy with most people. Like I said: match point!
If it were me, and I liked the way it played and sounded, I'd probably keep it and just ask them to swap the case for the one I ordered. That shouldn't pose a problem for them. But I don't buy anything with an eye on reselling. If I get something, it's always with the intention to play and keep it, so it's a lot easier for me than it is for some people.
Luck!