Clear Tail Lights

Hopefully someone will know AZ's code, but as far as FMCSA is concerned there is no mention of which part of the light has to be red, just that the light as a whole must shine red.

Here is the regs:
eCFR — Code of Federal Regulations

 

To my understanding the light must shine red, the lens can be clear, however if you are using a light/reflector combination the lens must also be red.

However my interpretations can be superseded by someone more knowledgeable than I, just like the FMCSA and DOT are always superseding interpretations in their book of law. I did just get a new copy of said book and can take a look in it in the morning. I can navigate that book a whole lot easier than their website.

 

Newer cars have em too.

 

SAE and us dot standards are only concern with the light being active, the SAE does the specs for the us dot and manufacturers follow.