When was the Yellow light MPX stereo introduced?

[Jeremy]

I have asked this question before in an older topic but recieved few answers. My 69 Camaro has the Yellow light pushbutton stereo with the hidden multiplex above the glove box. It appears to be untuched and very original to the car. It also has a sticker with a date that fits the build date of the car. I have been told that the Yellow light was first introduced in 1970, I have also been told that is incorrect. CRG is currently researching this same topic and states it may have been introduced sometime around June of 69? does anyone have any info on this topic? Thanks.