Love my LEDs, but I don't think I'll go for the FretFX.
Once they were cleaned, the dots are visible in regular light. Above the 12th fret, they are relatively visible. I think they're probably silver, so I will try to scrub them out a bit more.
I was looking for the glow dots since the house I bought most of 20 years ago had a wall with wallpaper that has a view of the earth from the moon with a little bit of moon-ground and there were those glow things all over the place. There's a set of dots specifically for this purpose on Amazon for $6 that I might try as well.