as a rider, i wear all black gear (no particular reason). but as a driver (and i've paid attention to the visibility of riders when i'm in my car - mostly out of curiosity regarding the perspective of drivers), have observed that it is the slight and irregular movement that catches my eye most often (somewhat similar to a squirrel or a bird, or even a plastic bag floating across the road). i see high vis clearly as it advances away, but rarely notice high vis approaching from behind any more than the movement previously mentioned. from a drivers perspective, bikes pretty much appear out of nowhere. and no amount of neon is going to change that fact.
