I reload both red and gray, even have some old silver ones and I haven't seen a bit of difference. They all break targets. The old silver ones have more space and I load those for 11/8 oz handicap. The red and gray 1 oz singles and sporting clays load. All loads at about 1180 to 1200 fps.
With my lot of Super handicap powder my Hornady #372 throws 20.2 grains. The next size Hornady makes is a #380 which throws 21.1. I bought another #372 and lapped it a bit to throw 20.6. I like to use the CB version of the TGT-12 wad with either Win or Cheddite primer. The published 20.9 load is over 11,000 psi so I like to back off a bit.