What color wire is the best?

When you say wires, you should mean the problem of distinguishing the quality of wires. At present, the most common good wire is copper core wire, and the others are of course synthetic materials. Let me talk about copper conductor here. The color distinction of copper core wire is: new copper (high purity original copper) is the best, a bit like gold, with red copper (less used) and slightly purple fracture. Almost all copper cores are made of recycled copper, the color is a little black, and the gloss is not good. There are also materials synthesized from recycled copper, which are characterized by being harder than pure copper, and the color is unusually yellow and mottled.