To identify U V W three-phase power often use colors to distinguish,U V W three-phase color,why?

Our country is:B for yellow,yellow,green and red A phase B phase for the green,phase C to red,neutral line (i.e.,zero) for light blue,protect the neutral line (ground) as the yellow and green double color Three-phase power supply how fork receiver method how to distinguish between ABC three brake rotor phase and ground wire? Phase color logo is:A phase for yellow;B phase for the electric motors 12 volt green;C phase in red.Or directly indicate the ABC phase.Ground zero line is blue,for double color line under normal circumstances,the plug or the wholesalemotor.blogspot.com socket

four conductive body,there is a show 90 degrees with other electrical conductor (sheet),whether it is a flake single phase asynchronous motor or columnar,the grounding end is longer than the other three,coarse.