I have a well optioned '69 SS/RS that was built in the third week of October 1969. I'm wanting to replace the aftermarket stereo with a correct GM stereo. I have a working Yellowlight and a working Bluelight but don't know which to use. I understand late production cars may have switched away from the Blue Light but I have never seen a factory installed Yellowlight in a '69 Camaro. Any insight would be appreciated!!

Thanks in advance!

You have asked a good question which I too have wondered about.
I have a factory installed blue light in my 03C Convertible. I removed a yellow light from a 05? something Camaro. The interesting thing about this yellow light is that it has the remote amp that mounts under the dash just like the blue light. Has anyone else seen a radio like this? I've seen one other. previous to this I thought all yellow light had a build in amp, no remote amp.
From what I've seen I would guess your late build car would have the yellow light. Does your yellow light have a remote amp?

That is interesting. This yellowlight has a built in amp. I don't know if it matters but it is out of an early production '70 Chevelle.

I believe the yellow light with amp is properly a transitional radio. Might be as simple as GM just ran out of the blue chips they used previously. Any input from the minds of camaros,net?

Buffalo,

I can't help much but I do know the plug-in on the back of a '70 radio is different than an '69.

By October '69 a factory-installed stereo would have been a yellow light.

Team Chevelle has a great section about radio's and decoding them:

http://www.chevelles.com/radiotech/

Worth a read.