By Miles Nicholson
Wire / Cable cores / Lens colour abbreviations should be in accordance with IEC 60757 (identical to CENELEC-harmonized document HD 457).
The following table shows the IEC colour abbreviations:
For combining colours no separator is necessarily required e.g. an earth cable which is green and yellow would have a colour abbreviation of “GNYE”.
For defining neutral cables where the blue is a light blue, then the abbreviation for light could be used i.e. “LBU”.