[cryptozoo]

It's simple, really -- if, in fact, zebras and double whites are more often hotter than their double black counterparts, then one could say that the bobbin color does make a difference. Not for the same reasons that seem to get you riled up, but it's still a difference. As for people removing covers to show white bobbins, the dork gene in humans always leans towards 'rare is better.' God knows, I've suffered from my share of it.