For cable labeling I've had good results with 3M Scotch Super88 color electrical tape. Pick unique color bands for each cable. Band it identically at both ends. You don't have to squint to see how it's labeled. And the label isn't invalidated merely because you unplugged it from one place and plugged it in somewhere else.
I usually use labels printed on all sides in about a 14 point font that have a unique number followed by a - and a length. So, for example, 10294-4.5 is a 4.5' long cable number 10294. You might need to squint a bit to read it, but, 14 points is usually pretty legible and being printed 4 times on the label (3 of which remain visible on the average cat5/cat6 cable) means you usually don't have to futz with twirling the cable to find the label. I usually have the labels installed ~2" from the plug at each end. In a crowded deployment, I think the color bands would be like trying to read resistor color codes in a box of ~1,000 mixed resistors. You're going to end up squinting anyway. With my tactic, you have the additional advantage that you get a defined search radius within which the other end can be located. Using serial-number labels instead of equipment-specific labels means that mine aren't invalidated either. Owen