Apologies if this is old news but I was looking at the DYMO label makers so that I can mark and catalogue my receivers/servos and monitor their usage.

I came across this one which also prints heat shrinkable tube that would be perfect for marking cables and tubes.

It is not cheap (it seems like there may be a cheaper version in the US) but looks like a great way of marking wires to ease maintenance and make sure you plug your servos into the right lead.

http://global.dymo.com/enUS/Products/RhinoPRO_3000.html