This is Square Hue First Flight:
Square Hue Decades set, which was in 2015, so this must have been in January. And of course this refers to the Wright Brothers - here is a good little page about the "first flight" day (it was in December, which I couldn't have told you).
I was already saying back then that Square Hue has a thing about grays, and I've gotten more of them since them. This is still the best of them, though, pale(ish) and shimmery. (I looked at this on both of my monitors and on one of them I'd say that this polish has just a hint of tan/sandy color to it. On the other I didn't see it.)
(I got an e-mail that had next month's Square Hue colors in it, because they are (finally) letting you pick and choose. Apparently 2017 is going to be dance-themed. Here's the January set.)