I believe this was a one-time only for the Knoxville jersey, the team will have one other promo jersey during the season, the other four home games, it will be home whites for the Nighthawks. Normally, these special jerseys are auctioned off to the fans after the game. And yes, the orange was a tie in to the Big Orange of Tennessee, including the checkerboard gussets.
Below is the special Alabama Hammers jersey from the Knoxville vs. Alabama game played in Huntsville several weeks ago, the jersey commemorates the Rocket City. The jersey numerals are lunar surface outlined in yellow. These jerseys were auctioned off to the fans following the game.