在日规标准里面的Appendix 1的的1.1.9里面,有写到“to the effect of earthing conductor" means that the earthing conductor is identified by arranged colours with green and yellow, letters of "protection earth," " preotection grounding" PE or codes sush 接地符号 (这个贴不上来)”
记得当时有打电话问日本JET,地线可以是纯绿和绿滚黄.