A question for those who have done their wiring looms, have you used various coloured cable or numbered

Cheers
Darren

At the last count I was up to 42 colours and I've still got to tackle the ECU !!

Just spliced them together so you end up with a multicoloured loom. As long as you know what does what and what goes where it's only a problem if you don't know what you've done.

Yep as per hellfire or you could number the wires by banding with a permanant marker or purchase slide on no's from the likes of maplins or RS components.

Both!!
I wrote everything down very carefully though.
My front and rear lighting looms are numbered but all black, and super top quality oil,heat,chemical and water resistant,especially supplied for external wiring on refuse vehicles.(dont ask).
The rest was standard Toyota engine loom multicoluored but usually matching the original Corrola diagrams.