I'm with Walt (I'm beginning to like you, Walt),
The Bright Sights works for me as it comes in a variety of colors, my favorite being the horrible flourescent green or orange. I purchased the entire kit direct from them to try out all the colors:
Green
Yellow
Red
White
Orange
They also make a glow in the dark coating that is, in my opinion, useless. Unless you have the firearm positioned under bright light immediately prior to requiring it, it does no good. They recommend mixing it with other colors, but even "straight" it isn't worth the time. I suggest night sights if that is a consideration.
The orange and green provide the highest contrast and are the most optimal of the five colors for low light. Red and white are essentially glosy and are not flourescent as the yellow, green and orange are. A vial of cleaner/thinner is provided in the kit for spills or mishaps or to "revitalize" the vial you forgot to close.
I've used white-out, model paints, nail polish; none adheres as well as the Bright Sights if the surface it is applied to is clean before application. It works exceptionally on sights if they are serrated (to reduce glare) for obvious reasons.
WESHOOT2 and I do the same thing. A toothpick or wooden dowel has worked best for me.
They have a website (do not have it handy) and I obtained mine from them.
Incidentally, they charged me less for it direct than any dealer in my locale. The kit with five the colors mentioned and the vial with the "glow in the dark" junk delivered was under $20, if I recall correctly.