Which color of the three wires is the ground wire?

Yellow and green.

If it is normal electrical wiring, live wire, neutral wire and ground wire are all wired according to wiring standards, then we can directly distinguish them from colors:

The fire line has three colors, namely yellow, green and red; There is only one color of the zero line, and that is light blue; There is only one color of grounding wire, and that is yellow and green.

Testing with a digital test pen:

1, if there is no leakage protection installed at home or it is on, then we can buy a digital test pen to measure voltage;

2. After power-on, we test the connectors of the three wires with a digital test pen, and see the voltage value on the digital test pen;

3. The highest voltage value is the live wire, the lowest voltage value is the ground wire, and the middle voltage value is the zero line.