Does the code address any specifics on the color of neutral wires in 120V residential wiring?

I always use white when I can, but in a pinch, say on adding a circuit tapped off an existing run, I have used other colors, such as blue for hot and yellow for return. Also, for color combos it is assumed that the darker wire is the hot and the lighter the return, though in various combos the same color could be hot or return---example; red and black, the red would be hot and the black neutral; black and white the black would hot and the white neutral, though this could be very confusing at the panel board. The wiring diagram on the package of a Plass outlet that I purchased indicated that only white, gray or green should be used for the neutral. I could see the white and gray, but the green is confusing in that I was taught it represents a ground, not a neutral. :confused:

I am sure that the NEC addresses this question about color of wires...
I just do not have the Book handy right now.
Hopefully somebody will be able to give you the article number.
White or Natural Grey are always Neutral in 120V AC circuits.
As far as Using other colors for neutral, don't do it.
Somebody could get hurt.
They do use different colors for hot wires. That depends on the situation.
In Residential wiring, the most common colors used for Hot are Red and Black.
Green or Bare is for Ground.
If you stick with these colors, you will be fine and anybody who has to work on this wiring after you will be safe.
Thanks,
c'ya