Greg suggested lines for better visibility, and set closer to the "leading" fret (the one that "stops" the tapped string and determines its length of vibration).
I agreed that a parallel strip inlaid close to the leading fret would highlight the fret itself, whereas the original centered dots accentuate the spaces between. I wanted each strip to run in a channel all the way across the board and have a substantial thickness so as to make their ends visible from both sides as well, especially from the bass side in direct player's view. The thin markers look pretty nice in various bold colored acrylic plastics, and they're in line-of-sight of the player, even over the Rail tips from an extreme viewing angle of 15 degrees or so (headstock inclined a bit inward toward the left shoulder in common playing position).
Some sets of strips are of a "glow" plastic material, absorbing light and glowing phosphorescent green in the dark. The glow fades away after an hour, maybe just in time for resuscitation between sets. By day they're a warm off-white, nice for Indonesian rosewood or charcoal black graphite. In the dark, just paint your fingernails a similar "glow" polish and you'll be color coordinated.