You might also find that the recesses that are drilled in the sights are deeper than they need to be, making the paint way in the bottom appear darker than it needs to be. You can fill up the recess somewhat so that the surface that you paint is just slightly recessed, making it seem brighter when finished. I did this using a drill bit to remove the existing paint, degrease with whatever you prefer, then press some quicksteel in the hole. Just the right amount of fingertip pressure on the still-soft quicksteel will leave a small indent that will protect the paint from wear.
I did this to my front sight, and filled in the rears completely to obtain my preferred sight picture.