Camouflage colours were so wide and variable, especially on helmets. If you take a look and do your research you will find that soldiers used all kinds of shades of paint, any they could get their hands on (obviously in the colours used). They also hand bushed the paint on them in many cases. The paint faded over time etc etc.
If you want your helmet to look brand spanking new with factory paint they used to spray the vehicles then yes go for that but I'm assuming you want a worn helmet look so don't be too worried about the EXACT paint colours - it wasn't that uniform.
Hope that helps.
Very much so, the logic that I follow is that every helmet I find I try to track down its history. For example, I have one that was found in Arromaches. So odds are is was issued to the 352nd infantry division. That gives me a very clear idea as to what that helmet would have looked like at that time. If it was found at a flea market or from a 3rd party, then that gives me a little more flexibility as to what I can do with it. Obviously I'm not gonna give a helmet found in Denmark a DAK finish, but you get my point/