@oldrooster
The black color of the bin's shell and the ability to easily and regularly turn it would indeed aid in quicker decomposition. However, there are some potential reasons why you might not want to do this with carcasses unless you can locate it WELL away from your dwelling.
The animal carcass bits must be covered liberally or it'll smell like death. I personally have no experience turning bins that I place carcasses into, primarily for the reason that it would encourage the stench escaping, and that all soft tissue animal parts that go in my bins get devoured by hordes of ravenous Blacl Soldier Fly larvae within a couple days. So the stinky period is usually short. But I still throw "brown matter" (leaves, sometimes a little soil, coconut husk bits, un-inked cardboard, rotting soft wood, bark, etc) and chunks of cardboard over and often under every carcass deposit. It helps the overall decomposition process of everything in the bin to have a mixture of more carbon-heavy (brown matter) and nitrogen-heavy (carcass) components. It also keeps the BSF larvae happy by giving them things to hide in; cardboard is their favorite from what I've observed. They burrow between the layers in droves.
If it is allowed to stink much, especially in temperate places where there's critters like raccoons, you can expect them to come looking for that free easy meal their nose tells them is available. Your coop setup muuuust be legitimately predator proof - totally secure. Feel free to add the raccoons etc it can bring in to the compost mix, or turn them into dinner first. I'm fond of the latter.
I use the BSF maggots as regular feed for my birds. The necessity in most cases of treating carcass laden compost a bit different from that without any animal parts has taught me to have separate BSF production bins and other non-carcass bins. I let the chickens periodically turn the latter for me. It makes them all kinds of happy and my back doesn't suffer over it.
Environmental temperature and ambient humidity levels will play a huge role in how fast your compost breaks down. Inclusion of BSF larvae in your system(s) will seriously expedite it *if* you include enough things they like to eat. They won't keep coming back to lay their eggs there if they're being starved out. Their two favorite foods as per my observations are rotten avocado and carcasses. They don't care what kind of animal it is, just that there's protein.
Hope this helps clarify a bit.