I have no idea if there are any standards out there and as long as it helps you know what's what I think that's all you can do. I've found the simpler the system the better so we just use the following:
Grey - Interconnecting Network devices (Router to switch, switch to switch, etc etc)
Green - Client machines/servers
Blue - Server iLo cards
I'd recommend using Cat6 cables now as the price has sufficiently come down to make it worthwhile - but that depends on what sort of network you have, speeds and all that kinda stuff.
We are pleased to announce availability of Beta software for 16.6.3. 16.6.3 will be the second rebuild on the 16.6 release train targeted towards Catalyst 9500/9400/9300/3850/3650 switching platforms. We are looking for early feedback from custome...