Cathodic Protection lines/Zinc Cables

What color do ya'll use? And how do you guys who mess around with them typically designate them? In GA were told to use red and the cathodic protection guys would bring red flags labeled for the gas company and indicating cathodic lines. But I'm in VA currently and typically yellow is used for all of it, but i don't know if that's the state standard or just this company's SOP.