07 turnsignal in headlight color

i was unfortunately ran into in a drive thru this august and after having the repairs finished, the new headlight seems a bit different than the older one. they only replaced one headlight because only one was damaged and they said they could not replace the other since it was an insurance claim. one head light, the older one, has a more yellowish tint to the lens on the turnsignal inside of the headlight, the other headlight, the new one, has a lens that is almost clear, very little if any yellow. after i noticed it i took it back and they said they ordered the wrong headlight, so they ordered another and when it came in it was the same deal; still a clear lens. they convinced me for the time being that the lens will fade to yellow over time???? does this sound right or should i go back for a third try at the body shop?? i cant imagine that a lens will fade to yellow but i guess i could be wrong. any help would be appreciated.