All I got is RED in Spartan 12 gauge 00 Buck...seen Yellow in different gauge....so check gauge on box and shell
Same here. I did an image search to see if I could find grey and only came up with red. Was gonna suggest the same thing, to check and see what labeling is on the box and brass.
Is it possible the grey is a low recoil load? What is the exact part number on the box? I can do some more digging yet.