O.C.G.A. § 40-1-6

Uniformed law enforcement officers of an agency who are assigned routinely or primarily to traffic law enforcement or other traffic safety duties on the roadways or highways of this state shall wear the same type uniform as other members of the assigned division of such officers’ respective agencies. Officers assigned to special operations activities may wear other identifiable uniforms or other clothing appropriate to an operation upon approval of the sheriff, chief of police, or other agency head. An otherwise lawful arrest shall not be invalidated or in any manner affected by failure to comply with this Code section.