A few decades ago, many foreign cars used to have amber rear turn-signal lights, but were required to have them in red for the US. I've seen a number of 60s-vintage classic imports at shows, where the owners installed Euro taillights, with amber turn-signals.

By the late 60s, there was apparently a rule change, and the imports, as well as many US cars started having amber rear turn signals.
I remember in the early '70s, a friend had a '68 Volvo 145 wagon with the red rear turn-signals and he broke a taillight, But even then, those early Volvo 145 lenses were very hard to find in junkyards, and the dealer only carried the updated amber versions, so if my friend decided to get a new lens, he would need to buy a pair!

Now I'm noticing cars since about 2000 have gone back to the red rear turn signals.
For example - my 98 Nissan Altima has red/clear/amber tailligts, but the nearly-identical 2000 or 2001 version has red/clear/red taillights.
So does someone know why? Was there another rule change, or (as I suspect) is it a cost-cutting thing?

Happy Motoring, Mark

__________________
DrDKW