Mandating a color code is not the intention of this code section. It simply suggests colors as one method of identifying voltages . You could just put little tags on all of the wires in your different systems and write "208/120" and "480/277" on them and meet this code requirement. Or you could use all purple wires for one system and all yellow wires for another. That would be a little redonkulous but would satisfy the requirement.
