I don't yet have a vast collection, but I have been planning for the future...
I label with a fine point silver paint marker. I can't do any more than a code, like R-1, J-3, ect. That means I have to keep the detail list in my e-book reader... So for my music, I currently have R-1, R-2, R-3, R-4, and J-1 for Rock 1 thru 4 and Jazz 1. Each 32 GBs. I ahve older, smaller ones that I currently don't use (I don't pitch anything that's working) Mostly 2 GBs and some 16 Gbs.
Gold color would work better but I couldn't find one at the time.