Last summer I was at a farm auction, and bought a whole stack of plastic
pipe. Most was rolled up, but a few were unwound and thus messy. No one
was very interested, because the stack was pretty messy due to the
unwound ones. So, I got the whole pile for a few bucks.

A few rolls are obviously poly pipe made for underground water supply
(black), but theres a roll of red, orange, and others that are 1/2 or
3/4" sizes as well as a roll of 1" red. Also a bunch of (unrolled) 3/8"
clear.

I think the clear stuff is some sort of dairy tubing used for milking
machines. But I'm not sure about that red or orange stuff. There is no
markings or words on it.

Is there any way to determine if any of this is PEX?

I dont really need it at the moment, but I'd like to try to identify
what I have.

For the price I paid, that black poly pipe alone was worth it, and that
3/8 clear stuff is good for tranferring gasoline, and hose for pump
insecticide sprayers, and other odds and ends around the farm. I already
got my money's worth from that clear stuff alone. But I'd still like to
determine what that other stuff is.....