What does it signify? There's one stud end painted on each hub.

 

wikipedia-tool

 

its just a check at the factory, you find them all over the car, some little dude/dudette checks to make sure stuff is done all down the line

 

Tire Rack, are you listening?

 

dude, you have a super rare type r lug stud!!!

 

they used to do that sometimes to indicate positioning for a locking lug, but when it comes to factory stuff like that, im not really sure. i checked around, and no one seems to know...even out local dealership!

 

Mine are green. I just put my lug locks on the marked studs.

 

The mystery deepens!

Mine are blue!

 

its a factory check mark and has NOTHING to do with where nuts go.
there are paint mark all over the car whre things are checked. that is one of the most overlooked things in concourse restoration the points lost for improper or missing paint marks.

 

Well, I hope it was an interesting question, then. I think on some cars it was used to indicate where to put the locking nut. But for now I will bask in the mystique of my super rare Type R lug stud!