So maybe this is a weird request, but does anyone know of any good permanent marker in white that could be used on a handgun for the rear sight?

Let me explain.  I carry a Kahr PM9 and really like it.  The sights are not a 3 dot like a Glock but Dot-the-l, and work quite well for quick target acquisition.   The back sight is black but has a white piece which fell out on my gun.  I guess I could get another piece, or another whole rear sight, but it doesn't inspire much confidence when the white piece falls out on me.  

The white piece (of plastic?) fits in a little grove, which if I could paint white, would serve quite well, and I wouldn't have to worry about it falling out.    

Am I crazy?  or has anyone done something like this before.  Should I just replace the rear sight?

Can anyone recommend such a marker?  I'm not sure if a metallic sharpie would work.  

I just paint mine. And if the paint starts to wear off, then just repaint them again.

Finger nail polish works well

I use model paint on a couple of fixed sight S&W revolvers.

Make sure you tape it off to make it look professional.

Use very little paint..... I use a toothpick to paint with.

One of the rear dots on my USP did that. I used paint from a hobby store. I used white as a base coat and used luminescent paint over that. It glows extremely bright with small exposures to light and makes for cheap and effective ghetto night sights.

I used white out when I was in a pinch one day. It held up fine for a while until I got some new sights. So if I were you I would just pick up some white paint and a small applicator.

http://www.midwayusa.com/viewproduct/?productnumber=176851

I got some of this to put on the sights of my P22 but haven't had a chance to apply it yet.