Not sure how old, but I see a lot of these on the road. When the driver hits the brakes, it looks like two sets of lights flash. There's a pair of lights inside that flash, but typically they seem almost white like they're backup lights. However, when I look at them closely, it looks like the lens material used to be red but has faded over time, with maybe a thin fringe of red at the edge of the lens. What's the deal with these?