Rear sight numbers

[dash 0]

It appears the numbers on the rear sights can be filled in with white, yellow or nothing. Is any one more common than the others?? Was one done on the early rifles and the others done on later ones? How are the Miltech/Winfield ones done up?

Mine are red and it doesn't look like it was done recently. Anyone else have red numbers?

[Joseph Scott 0]

I have seen many original sights and none had paint in the markings.