Those to not appear to be "plies" to me in the structural sence. They appear to be the cloth wear indicator that is often layed over a portion of the last with a retread. It is often refered to as the first ply but has no real structural value.
I believe I am correct in saying there are usually 2 more layers of chord before the carcass chord which is red. Usually other than catastrophic failure the only way to see a carcass chord is with a deep cut. and there are plenty more layers of chord below it.