From everything I've seen so far it looks like yes, it's the "I don't need storage color". Not sure what not exactly.. Possible Google thought they wouldn't sell many of that color and wasn't worth the expense on there part or maybe blue food coloring is more expensive. O wait..lol
It's weird tho, I mean, why wouldn't them have their limited color edition in their most expensive model? It would make more sense to have the limited one in the most expensive models, like the iPhone 7 jet black.