I bought this date accumulation of Coronet style large cents dated from 1816-1834 as a study group. I want to "play" with these over time and see how they look after a bit of "circulation" in my pocket change. There are already things that stand out with this group of cent fakes - 1. The dates are still a problem, they have the last digit off, or as in the case of the 1820's dated cents the serif on the numeral 2 is just overdone. 2. To age the coins and make them look more "authentic" it is readily apparent that after they strike them, they are red and brilliant - but they would stand out as fakes - so the forgers heat the pieces up in a furnace which accounts for the smoky greyish blue haze on the pieces. On first sight that is what links all of them together, that haze from the heating process that aged and darkened them. 3. The 1820's dated cents stand out because the last numeric digit in the date is a bit clumsy 4. For some curious reason the 1830's dated cents have smaller dates that don't look quite right. 5. The hazy film on the coins can be rubbed away with a very fine jewelers cloth - this is where these coins become more dangerous as forgeries - obviously the forgers think they have done enough, and maybe this is just too labour intensive even for them with their cheap labour there. These fakes are not going to convince serious collectors, but they are good enough to be a problem for more novice collectors, especially if they are aged with wear, damage etc.
They all have that odd "shadow" edge that immediately strike me as cause for concern. Also, as you note, the color is a bit off (not that unusual though) and the dates are wrong. I would expect careful inspection to identify other problems. However, at first glance, they are pretty good copies. Scary.
I will post images in the future as I "work" on these in an effort to make them more authentic looking this is a work in progress experiment. I have a restrike 1794 cent that I play with from time to time as an occasional pocket piece to see how it ages over time. I want to play with these as an educational and informational learning experience and then after I am done I will put them out of their misery and use them for skeet targets or something.