Artist's description from DA:I can safely say that this pony in particular will be getting more vectoring attention from me in the future.
There was a bit of improvising for his eye and the yellow ring around the holes for the forelegs on the uniform. I guess the artists for the stallion version of the uniform were more lazy compared to the mare version just like most stallion-vs-mare-related things, since the stallions tend to just be background props anyway. For the eye, I recycled an eye from one of my other vectors and edited the iris and pupil; I felt I'd rather go with a look I knew would at least be relatively accurate than try to do an eye from what little we see of his eye with his foreleg and goggles in the way.
Speaking of the eye, I've also done it in an identical shade of green I've used on another pony like in the show, even though his eyes are gold like 's before he gets the uniform. Versions with gold eyes are linked separately toward the bottom if you prefer those. I'm assuming from a layout artist's perspective that with two white stallions and a dark-gray stallion, two of those stallions with identical eye color, there was need for a little variety, and since no one pays enough attention to background ponies, let alone background stallions anyway, the eye color of this pony was changed as soon as the stallions started standing next to each other. From a headcanon-ing perspective I'd assume he wears blue corrective contact lenses…or something. I also think of him to be a nerdy pegasus with how he was one of the weakest fliers in the group alongside his look and impression.
His badge may also missing in the original shot—despite him appearing and me vectoring him facing this way in the past, I've attributed it to his badge being on the side of his torso that is not facing this way and thus is not seen. Although I also feel that it's only important to add the badge if necessary when appearing alongside a corresponding leadpony, which doesn't happen here.
Finally, about his name—the most popular name by upvote for this pony was "Milky Way", but an, erm, "questionably popular" OC of the same name had this pony's name changed to "Mercury" on Derpibooru's tagging system, so I will be referring to him as Mercury as well to avoid association with the other pony.