Originally Posted by
twinquad
I think the reasons for red covers are (1) insofar as the taillight acts as a reflector, it will be a red reflector, and (2) people might think a light with a clear cover wouldn't produce red light. We're used to car taillights which have to have red covers to filter the broad-spectrum light coming from the incandescent source.
As far as (1) goes, there aren't many lights with built-in reflectors, and the PBSF is one of those that, despite its looks, does
not have a reflector (I've tried to see what it could do, and it doesn't reflect worth a darn). In many cases, that part acts as a dispersion lens instead of a reflector.
(2) is pretty true; you see a red lens and you expect it to produce red light, so it's an easier selling point. But, yeah, we're getting used to seeing car taillights that are clear yet produce red light (the Prius and a Lexus SUV, for example).