My 1853 proof penny (below) is somewhat like that, although the very attractive reddish portions on the reverse don't show up to well on the photo. I reckon it has to catch the light in a certain way to be readily visible. I think it came from a set but not certain.
Interestingly, there were only 40 sets minted according to information in Coin News as it related to the Tyrant collection - link - but there surely has to be more proof pennies than that, purely from observation. Although when and why the extra were minted is a mystery. Moreover, Peck says there is a bronzed copper proof from 1853, with an inverted reverse. Never seen one advertised though, or seen one anywhere come to that.