Here's the information on the (SG) "Autobot Elite Guard"
The ELITE GUARD is a small contingent of Autobot soldiers who have filled the power vacuum left by the destruction of the "Wreckers." While the Wreckers were a group of mercenaries and assorted malcontents, the Elite Guard are professional soldiers who follow the orders of their leader, THUNDERCLASH, unswervingly.
That page also has some "designer's notes," suggesting that SG Thunderclash was intentionally given a "boring" color scheme to contrast with the colors of the BotCon toy. He was given a personality based on Erwin Rommel.