It's no use to show you a picture of my bird nest of wires under a seat, because my stuff there is very different from stock. Being in your shoes I'd rewire it myself, because your loom will be also different from stock, and make a diagram from my own wiring kept in a manual
with the bike. You could order original colored wires from British Wiring, but it going to be not stock anyway, so for me doesn't matter.
In my Trident case I just used my original loom, but has to discard and change ignition part ( Trispark
) and charging part ( 3 phase alternator + reg/ rec ) so only lights and horn stayed original.