Armor

The original ARCs wore advanced variants of Clone Trooper armor with blue coloration. Until an enemy closed in with them, it was impossible to discern what Republic forces one would be facing. This was an asset to the psychological effect of ARCs as enemy would actively charge against the massive firepower and superior training of an ARC unit, not realizing until too late that they were far outmatched.

Image credit: Dark Horse comics

Later in the Clone Wars, a more advanced tactical armor set was created for use by Republic Commando units.