paul — In the 1953 NEC Handbook the green/bare permission/use limitation is stated. Reidentification was permitted "by paint or other effective means."
Living in a rural area, I came across local 480Y/277V in plants that had medium-voltage service, and in sports-field lighting. The first significant recommendation I found in text is the classic 1955 Industrial Power Systems Handbook, by Donald Beeman.
In many older plants and commercial/institutionals, coloring is black-black-black(-white)+bare or metal raceway. Differing voltages having distinct phase identification varies, but I’ve found it in 1957-vintage institutional/research facilities.