In addition tho my previous posting, I'd like to add that I tried some paints I bought at a gun store once for this. They came in tiny vials and I picked out flourescent orange and yellow to try. I was seriously disappointed. The paints required several coats on my black sights to build up a significant enough coating to be plainly visible. And even so, it was disappointing. I don't remember what I paid for them, but it wouldn't have been worth it if it was free. I'm sure I've still got them somewhere...if find them I'll post a pic. Next time I do this I'll be using some bright nail polish instead.