amber lights vs red: ambers cracked, reds not.
This is kind of an oddball question/observation. While examining the lights on our bus, I noticed every single one of the amber light lenses (Weldon, markers & flashers) were riddled with age/stress cracks (those tiny spiderweb cracks you can barely see), while the reds were clear as a bell. There was no sign whatsoever the reds had been swapped out or were newer... I'm fairly certain red & amber alike are original equipment.
Does anyone know the reason for this? Slightly different plastic composition? Differences in light transmission? Reds reflecting wavelengths that create these micro-cracks where amber does not?
I'd provide pics, but the cracks I'm talking about are so fine, they wouldn't show.