I use floresent orange on my gongs and they really stand out.
One of the best shooters (or the one that I can shoot the best) is my Model 64 I use in ICORE.
The 64, being stainless makes it really hard for me to concentrate on the front sight. I took some of the floresent orange paint and put it on the front sight. That sucker jumps right out almost forcing you to concentrate on the front sight.
Took a dab and put it on the white dot on the front sight of my Beretta 92 and again, it stands out.
Its cheap, stays on pretty good, (only do a touch up at the first of the shooting season) and easy to do.