According to Variety, the suit is designed by Laura Jean “L.J.” Shannon and concept artist Greg Hopwood. They went with the military green since in the comic book "The Boys" Soldier Boy is the original bad-ass. According to L.J. Shannon, “Our goal was to highlight a bygone era of overt masculinity and grit. With that pedigree we dove headfirst into baking in an all-American quality grounded in a military soldier’s practicality with a heavy dose of old school cowboy swagger. We knew that the actor had to have Steve McQueen looks and chops with a John Wayne attitude — luckily Jensen Ackles embodies all of that.”
For those that have watched season one and two on Amazon Prime, Compound V plays into Soldier Boy's history. He was created from Compound V in the 1940's, thus becoming the "original" supe. He was the first Homelander! He was a big hero in World War II, dodging bullets and killing Nazis by the dozens. The shield is his primary weapon, and Jensen shared a closer look of it's design on his Instagram page:
Edited: Here's more stuff from Jensen's Twitter:
Here's an awesome quote from the biggest fan boy of this popular character's new look, Eric Kripke:
“When I cast Jensen as Soldier Boy, the first thing I said was, ‘I’m most excited for you, because of the amazing process you’ll go through with LJ, our Super Suit designer. It took six months but the experience surpassed Jensen’s expectations. L.J. has made a work of art that tips its hat to the WWII Soldier Boy from the comics, while taking it in a sleek new direction. And if you think the photos are cool, just wait till you see Jensen in action. It’s one of my very favorite suits. Also, now you can quit clogging my Twitter notifications with demands to see it.”
Thank you Mr. Kripke, we are satisfied. We can't wait to see Jensen in action either! Until season three drops, check out seasons one and two on Amazon Prime. That way you're up to speed for this latest twist.