I load 12 & 16.
The 12's are Winchester compression formed hulls & I have thousands. They come in red, black Hi brass & black low brass, gold & orange.
I have enough of the colours to load low pressure 7/8 oz, 7 1/2 in red, low pressure 1 oz, 4's in low brass black. Hi pressure 1 1/8 oz in hi brass black & so on. I do not put some colour shells in some guns, while other guns can be fed any colour.

The 16's are shot size by colour, purple, red, green & blue & all the same 3/4 oz load other wise.
O.M