... For Flat Twin with or without E.C.C., Flat Three Core, PVC sheath General Purpose) PVC Insulation: Type A of ... plan. Colour for Core identification & colour sequence: (1) Single Core - Red, Black, Yellow or Blue. (2) Two Core - Red & Black, (3) Three Core - Red, ... Yellow & Blue(4) Four Core - Red, Yellow, Blue & Black Colour of ...