Looks like the Camaro has a thicker white wall. I think you are correct on the reason why it wasn't a Goodyear.
I'm working on what we can eliminate as paint colors;
Certainly not Dark Moss Green, Nightmist Blue, Black, or White.
Not Bronze as the only GT500 car built was a manual.
Looks too light to be Gray and as it turns out there were no Gray GT500s built. (the one car thought to be gray turned out to be factory Lime Gold)
That leaves Brittany, Lime, Red, or Acapulco...
edit; leaving us with approximately 349 automatics