[PDF] COMMONLY USED COLOUR CODES FOR BRITISH CAR WIRING COMMONLY USED COLOUR CODES FOR BRITISH CAR WIRING Colour Main/Tracer Use BROWN Main battery feed Brown/Blue Control box to ignition and lighting switch (feed) Brown/Red Compression ignition starting aid to switch. Main battery feed to double Motorcycle Wire Color Codes – Electrical Connection Mar 08, 2016DISCLAIMER. Let’s get this out of the way, right meow. This listing is a GUIDE. If you don’t check before you connect, please list all your tools for sale on Craigslist.