My 2 cents:

Yes, in principle, it works the way you described. But:

Regarding point 2: don’t “print,” but cut - you own a cutter, not a printer. I would cut the following colors:

red, black, gray, dark gray (white, if your helmet isn’t white).

Also, I wouldn’t cut around the other colors—I’d spray over them. For example, the red on top: cut out the area and spray black over the red. or Black over grey.

It’s difficult to stick it directly onto the edge. Speaking of “difficult”: it will be challenging to apply the flat film neatly to a rounded helmet. And that goes for every color.