Parkerizing is just one type of finish that works well. Lube-rite(it's a trade name) is the same idea and is the finish seen on C1A1's, but is a much more modern finish. Not by many years though. Pure Parkerizing is usually shades of grey, but it can be darker(close to black). Lube-rite is always black. Either one works well on a hunting rifle though.
Green parkerizing is the result of long term storage in cosmoline. There was no W. W. II green parkerizing.