How Lighting Circuits Were Wired - Old Cable Colours Explained Connections and conductors in a ceiling rose and pendant with the old cable colours RED and BLACK. We look at the layout of a ceiling rose and its connections - loop, neutral and switching line but this time with the cable colours from pre 2004. At college we often have only 2 twin and CPC (twin and earth) cables at the lighting points and they are in different conductor colours during training but often in the real world this would