Gray Pipe okay for TPR?

Does anyone know if this gray pipe is okay for use with a TPR? I don’t want to call it out, if it is.

Without being able to see any markings, I would call it as being PVC (which I believe gray pipe is), which is not approved. I’m not sure if there is a gray CPVC pipe. Is the relief/test handle too close to the wall/trim to operate? If so, I would call it out for that (unable to operate).

Thanks Jeff, That’s what I was thinking.

Schedule 80 CPVC is grey. Then again, so is electrical conduit, but that’s PVC.

The plumbers and municipal inspectors have no problem with it here in my neck of the woods. I almost always find it in manufactured homes.